Official Glossary of Pontoon Boating Terms

Below is a glossary of 100 essential pontoon-related terms, arranged in alphabetical order. Each term is defined clearly and concisely, covering pontoon boat parts, navigation terminology, maintenance concepts, and general boating ideas. This dictionary-style list is intended for readers with basic to intermediate boating experience.

A

Aft: Toward or at the back end of the boat (the stern). For example, the rear seating area on a pontoon is toward the aft.

Aground: When a boat’s underside (hull or pontoon) is resting on the bottom (shore or submerged ground) instead of floating freely in the water. A boat that has run aground needs to be refloated by reducing weight or waiting for higher water.

Amidships: The middle section of a boat, halfway between the bow and stern. If something is located amidships, it is roughly in the center portion of the pontoon boat.

Anchor: A heavy device (usually metal) lowered to the bottom of a lake or river on a rope/chain (rode) to hold the boat in place. Anchors dig into the soil or catch on the bottom to moor the boat so it doesn’t drift with wind or current.

Anode (Sacrificial Anode): A piece of soft metal (often zinc or aluminum) attached to the boat’s underwater metal parts (like the pontoon tubes or engine). It corrodes (sacrifices itself) instead of the important parts, protecting them from galvanic corrosion in the water. Anodes need to be checked and replaced when mostly dissolved.

Anti-fouling (Paint): A special marine paint applied to the bottom of boats or pontoon tubes to prevent marine growth (algae, barnacles, slime) from sticking. Anti-fouling paint helps keep the hull clean (reducing drag) and protects against organism buildup, a process known as fouling.

B

Beam: The width of a boat at its widest point. On a pontoon boat, the beam is measured across the deck from side to side. A wider beam generally means more deck space and stability.

Bilge: The lowest interior area of a boat’s hull where water can collect. In many boats, any water that enters (from rain or splashes) runs down into the bilge.

Bilge Pump: A pump (manual or electric) used to remove unwanted water from the bilge. If water accumulates in the pontoon’s bilge area (for example, in the motor pod or any compartment), the bilge pump expels it overboard to keep the boat dry.

Bimini Top: A canvas or fabric canopy supported by a metal frame, typically mounted to the pontoon’s deck. A Bimini top provides shade and protection from sun or light rain. It can usually be folded down or removed when not needed.

Bow: The forward end or front of the boat. The bow of a pontoon boat is often where forward seating is located, and it’s the end that cuts through the water when moving forward.

Buoy: A floating marker used in waterways for navigation or mooring. Navigation buoys mark channels, hazards, or boundaries (often colored red or green in channels), while a mooring buoy is a floating anchor point that boats can tie up to. Buoys are anchored to the bottom so they stay in place as reference points.

C

Capacity Plate: A placard on a boat (usually near the helm or by the driver’s seat) that states the maximum weight, number of passengers, and engine horsepower the boat can safely handle. For pontoon boats, the capacity plate tells you the limit of people or weight to avoid overloading.

Catamaran: A boat with two parallel hulls. A pontoon boat is a type of catamaran in principle, since it uses two (or sometimes three) pontoon tubes as flotation hulls. Catamarans are known for stability due to their wide stance.

Cavitation: A phenomenon where a propeller creates low-pressure bubbles in the water that then collapse. Cavitation typically happens if the prop is damaged or spinning too fast, forming vapor bubbles on the blades. It can cause a loss of thrust and even damage the propeller over time (due to the imploding bubbles).

Chartplotter (GPS): An electronic navigation device that uses GPS (Global Positioning System) to display the boat’s position on a digital map (nautical chart). A chartplotter helps the pontoon captain navigate waters by showing depth contours, landmarks, and navigation aids, often combined with functions like fish-finder sonar.

Cleat: A metal fitting on the boat (often on the deck edges) used for securing ropes. Cleats have T-shaped or horn-shaped ends; you tie dock lines or anchor lines around them to fasten the pontoon to a dock, anchor, or another boat.

Compass: A navigation instrument that shows direction relative to the earth’s north. A magnetic compass on a boat helps the driver maintain or determine headings (e.g., going east or west) when navigating, especially if electronic GPS fails or isn’t available.

Console: The control station on a pontoon boat, typically a helm console. It’s the structure that houses the steering wheel, throttle controls, ignition, gauges, and often switches for lights and accessories. Many consoles also have storage space and areas to mount electronics.

Crossbeams: Sturdy, lateral beams (usually aluminum on a pontoon) that span across the pontoon boat’s width, connecting the pontoon tubes and supporting the deck. Crossbeams are part of the substructure, acting like floor joists, giving the deck a stable platform to sit on.

D

Deck: The flat platform on top of the pontoon boat where passengers and furniture sit. It’s essentially the “floor” of the pontoon, usually made of plywood or composite boards covered with carpet or vinyl. The deck is supported by the pontoon tubes and crossbeams beneath it.

Depth Finder (Fish Finder): An electronic sonar device that measures water depth and often displays underwater features or fish. It usually has a transducer mounted beneath the boat that sends sound waves down and reads the echo. This helps pontoon operators avoid shallow areas and is useful for fishing (showing fish and depth on a screen).

Displacement Hull: A type of hull design that moves through the water by pushing it aside (displacing it), rather than riding on top of it. Pontoon boats at low speeds act like displacement hulls — the tubes plow through water. Displacement hulls are very stable and carry heavy loads well, but generally have lower top speeds (they don’t plane out).

Dock: 1) Noun: A structure where boats can be secured, usually consisting of a platform or pier extending over the water. Pontoons are often moored to a dock using ropes on cleats. 2) Verb: To dock a boat is to bring it to the pier and secure it. Docking typically involves slowly maneuvering the pontoon alongside the dock and tying it up.

Draft: The vertical distance from the waterline down to the lowest point of the boat’s hull or pontoons. A pontoon boat’s draft is typically shallow (often a couple of feet or less) because the pontoon tubes don’t sit very deep. A shallow draft lets pontoons operate in relatively shallow water without grounding.

Drain Plug: A plug (stopper) in the boat’s hull or pontoon tubes that can be removed to drain out water. On traditional boats, the drain plug is often at the transom to empty water from the bilge when on land. Some pontoon tubes also have small drain plugs for releasing any water that may seep inside the tubes.

F

Fender: A cushioned bumper placed between the boat and a dock or another boat to prevent damage. Fenders (often cylindrical or round and made of rubber or inflatable vinyl) are hung over the sides of a pontoon so that when it rubs against a pier, the fender takes the impact, protecting the pontoon’s fence or tubes.

Fence: The railing or side panels that surround the deck of a pontoon boat. The fence usually consists of aluminum panels and railings and is about waist-high, enclosing the deck area (often called the playpen). It provides safety (keeps people and gear from sliding off the deck) and some protection from wind and spray.

Fore (Forward): Toward the front or bow of the boat. It can describe a direction (moving fore = moving forward) or a location (the fore deck = the front deck area). “Fore” is the opposite of aft.

Freeboard: The vertical distance from the waterline to the top edge of the boat’s deck or hull. In a pontoon boat, it’s measured from the water up to the deck (or to the top of the pontoon tubes if they sit lower than the deck). A higher freeboard means the deck sits well above water (helpful in waves to keep passengers dry), whereas low freeboard can get you wet in choppy water.

Fuel Stabilizer: A chemical additive for gasoline used when storing a boat for extended periods (especially over the winter). Fuel stabilizer is mixed into the gas tank to prevent the fuel from breaking down, gumming up, or absorbing moisture during storage. It ensures the engine’s fuel remains fresh and the motor will start up reliably after storage.

G

Galvanic Corrosion: A type of corrosion that occurs when two different metals are in electrical contact in water (an electrolyte). For example, an aluminum pontoon and a steel component in water can set up a tiny electrical current that causes one metal to corrode faster. Sacrificial anodes (often zinc) are used to prevent galvanic corrosion by attracting the corrosion to themselves instead of the boat’s vital parts.

Gate: A small swinging door in the pontoon’s fence that allows people to enter or exit the deck. Gates are typically located at the bow (front gate) and sometimes on the side or stern. They latch closed for safety when underway. A bow gate, for instance, lets you step onto the bow deck or a dock when opened.

Gunwale (Gunnel): The upper edge of a boat’s side. On a pontoon boat, this term can refer to the top rim of the side fence or the edge of the deck. Traditionally, in other boats, the gunwale is the reinforced edge at the top of the hull’s sides. (Pronounced “GUN-nel.”)

H

Helm: The steering and control area of a boat. On a pontoon, “the helm” typically refers to the driver’s console with the steering wheel and controls. For example, the captain sits at the helm to steer and operate the pontoon.

Hull: The main body of a boat that sits in the water. Pontoon boats have multiple hulls (two or three aluminum pontoon tubes act as hulls). In a traditional sense, the hull includes any part of the structure that provides buoyancy and slices through the water. Everything below the deck on a pontoon (the tubes and support frame) constitutes the hull for that boat.

Hull Identification Number (HIN): A unique serial number assigned to a boat by the manufacturer, similar to a car’s VIN. The HIN is typically engraved or stamped on the transom or aft portion of one pontoon. It identifies the boat’s manufacturer and serial, which is used for registration and insurance.

Hydrodynamic Nose Cone: The pointed forward tip of a pontoon tube. This nose cone is shaped to cut through the water smoothly, reducing resistance. Hydrodynamic nose cones help the pontoon glide through water by deflecting water around the round pontoon tubes and improving the boat’s efficiency.

I

Impeller: A rotating component in a pump that moves fluid. In boating, “impeller” often refers to the rubber vaned pump wheel in an outboard motor’s water pump. The impeller in the engine’s lower unit circulates cooling water through the motor. (In jet-driven boats or personal watercraft, the impeller is a sort of internal propeller that pushes water for propulsion.)

Inboard Engine: A boat engine mounted inside the hull, rather than outside on the transom. Inboard engines are common in ski boats and larger yachts (mounted mid-ship or in the stern inside the boat). Pontoon boats rarely use true inboards; they usually have outboard engines. (When pontoon manufacturers talk about inboard in a pontoon context, they usually mean a stern drive, which is a hybrid inboard/outboard system.)

J

Jack Plate: An adjustable mounting bracket for an outboard motor. It allows the engine to be raised or lowered vertically on the transom. Jack plates are used to improve performance – for example, lifting the motor for shallower running on a pontoon used in skinny water, or optimizing prop depth for speed. By adjusting a jack plate, you can change the motor’s height without altering the transom.

K

Keel: The central structural strip or backbone along the bottom of a hull in traditional boats. On a pontoon boat, there isn’t a single keel because there are multiple tubes; however, each pontoon tube often has a keel-like reinforcement or a fin underneath. The keel (or keels) help with tracking and protecting the bottom of the boat. In general boating, a keel provides stability and directional control in the water.

Kill Switch (Safety Lanyard): An emergency engine shut-off switch that is connected to the captain by a cord (lanyard). If the driver is thrown from the helm or moves too far away, the lanyard pulls the kill switch and instantly stops the engine. This safety device prevents a runaway boat scenario. Modern versions can be wireless fobs, but many are a simple coil cord clipped to the driver’s life jacket or wrist.

Knot: 1) Speed: A unit of speed equal to one nautical mile per hour. Boats’ speeds are often given in knots. For reference, 1 knot is about 1.15 miles per hour (1.85 km/h). For example, a pontoon going 10 knots is traveling roughly 11.5 mph. 2) Nautical knot: a term for tying rope, but when boaters say “knot” without context, they usually mean the speed unit.

L

Ladder: A boarding ladder attached to the boat to help people get on and off, especially from the water. Pontoons often have a folding ladder on the stern (back deck) or bow that can be extended down into the water, making it easy to climb back into the boat after swimming.

Length Overall (LOA): The total length of the boat from the furthest forward point to the furthest aft point. On a pontoon, LOA includes the bow deck (or any bow-mounted gear) all the way to the end of the motor (if the motor sticks out past the deck). It’s used for identifying the boat’s size for docking space, trailer size, etc. (Note: sometimes pontoon deck length is a bit shorter than LOA when the motor and ladder extend beyond.)

Line: In boating, nearly all ropes are referred to as “lines” once they are put to use. For example, dock lines are ropes used to tie the pontoon to the dock cleats, and an anchor line is the rope connecting an anchor to the boat. Lines can have specific names by purpose (anchor line, bow line, stern line, spring line, etc.), but “line” is a general term for any rope on board.

List: The tilt of a boat to one side (port or starboard) when not centered. A pontoon boat generally shouldn’t list much due to its twin-hull stability, but it can list if weight is unevenly distributed (too many people on one side) or if one pontoon tube is taking on water. “Listing” means the boat is leaning sideways rather than sitting level.

Livewell: A built-in tank or well on a fishing boat (including some fishing-equipped pontoons) that holds water to keep caught fish or live bait alive. A livewell has a small water pump (aerator) that continuously brings fresh water in (or recirculates water) to provide oxygen, essentially acting like a portable aquarium on the boat for fresh catches.

Log: In pontoon terminology, a “log” refers to one of the hollow aluminum tubes that provide the boat’s buoyancy. Standard pontoon boats have two logs (tubes) and “tritoons” have three. Logs are sealed to trap air, and they allow the boat to float. (They are also simply called pontoons or tubes.)

M

Marina: A facility on the water where boats are kept and serviced. A marina typically has many docks or slips for mooring boats, as well as amenities like fuel docks, boat ramps, electricity, and sometimes repair services. Pontoon owners might rent a slip at a marina for the season to keep their boat in the water.

Marine Radio (VHF Radio): A two-way communication device used on boats to hail other boaters, communicate with marinas, and for emergency calls. VHF stands for Very High Frequency. A fixed or handheld VHF marine radio on a pontoon is used to monitor channels (like Channel 16 for distress) and can be vital for safety, allowing one to call for help or get navigation information.

Mayday: The internationally recognized distress call used over radio to signal a life-threatening emergency on a boat. If a pontoon boat were in grave danger (sinking, fire, etc.), the operator would broadcast “Mayday” three times followed by details of the emergency. (Less dire emergencies use “Pan-Pan” or “Sécurité” calls, but Mayday is for immediate help needed.)

Mooring: Securing a boat to a fixed point. This can refer to tying a pontoon to a dock (using lines on cleats), attaching to a mooring buoy, or dropping an anchor to hold position. As a noun, a “mooring” can mean a permanent anchor or buoy setup that boats tie to. As a verb, to moor means to make the boat fast to something so it stays put.

Motor Pod: An extension or pod at the stern of some pontoon boats, specifically designed to hold the outboard engine. It’s like a mini platform or box that hangs off the back between the pontoon tubes. The motor pod provides a solid mounting surface for the engine and can improve performance by positioning the engine correctly relative to the pontoons (often allowing for a larger engine or better weight distribution).

N

Nautical Chart: A map designed for boating, showing bodies of water with depths, navigation hazards, channels, and aids to navigation (like buoys and lights). Nautical charts can be paper or electronic (as used in a GPS chartplotter). They help pontoon operators avoid shallow areas and find safe routes, especially on unfamiliar lakes or coastal areas.

Nautical Mile: A unit of distance used in marine navigation, equal to 1.852 kilometers or about 1.15 statute (land) miles. Distances on water and in international navigation are usually given in nautical miles. For example, if a marina is 5 nautical miles away, that’s about 5.75 regular miles. One nautical mile corresponds to one minute of latitude on a chart.

Navigation Lights: The required colored lights a boat displays at night or in low visibility so other vessels can determine its orientation and status. A typical pontoon boat’s navigation lights include a red light on the port (left) side, a green light on the starboard (right) side (often these are combined into a bi-color bow light), and an all-around white light (anchor light) at the stern or on a pole. These let others know your boat’s position and direction of travel in the dark.

No-Wake Zone: An area where boats must travel at idle speed, producing no wake (minimal waves). These zones are often found near marinas, docks, swimming areas, or in narrow channels to prevent erosion and ensure safety. When operating a pontoon in a no-wake zone, the driver should go slow enough that the boat’s wake is negligible – essentially just above neutral gear or idle. Signs or buoys usually mark these zones.

O

Outboard Motor: A self-contained engine mounted on the outside of the stern (transom) of a boat. It includes the engine, gearbox, and propeller in one unit. Pontoon boats almost always use outboard motors for propulsion. Outboards can be tilted up out of the water when not in use and are known for being easy to service or replace. They come in various sizes (horsepower) to suit different pontoon lengths and performance needs.

Overboard: Over the side of the boat into the water. If something falls off the pontoon, it’s gone “overboard.” This term is also used in emergencies – for instance, “Man overboard!” is shouted if a person has fallen into the water from the boat, prompting a rescue procedure.

P

Personal Flotation Device (PFD): A life jacket or life vest – a wearable piece of equipment that helps a person stay afloat in water. Coast Guard regulations require a PFD for each passenger on board. PFDs come in various types, but on a pontoon, typically you have foam vests or inflatable life jackets. Wearing a PFD is essential safety practice, especially for children or non-swimmers.

Planing: The mode of operation when a boat accelerates enough to rise up and skim on top of the water rather than plowing through it. Some pontoon boats, especially those with powerful engines or three tubes (tritoons with lifting strakes), can achieve a partial plane – they ride higher, with less of the hull in the water, allowing greater speed. “On plane” means the boat is gliding on the surface, which reduces drag.

Playpen: A casual term for the main passenger area on a pontoon boat’s deck, enclosed by the fence. It’s where the seating, tables, and carpeted deck are – essentially the “cockpit” or living room of the pontoon. The fence around it makes it resemble a playpen. You might hear, “Kids, stay in the playpen area,” meaning stay inside the fenced part of the deck.

Pontoon: This term has two related meanings. (1) One of the buoyant tubes or floats under the deck of the boat. A standard pontoon boat has two aluminum pontoons (tubes) that provide its floatation, and a tritoon has three. (2) The word “pontoon” is also used to refer to the entire pontoon boat. Pontoon boats are flat-deck boats that rely on pontoon tubes for buoyancy, known for stability and spacious decks.

Port: The left-hand side of a boat when you are facing the bow (forward). If something is on the port side of a pontoon, it is on the left side when looking toward the front. Port is indicated by a red light at night. (An easy memory trick: “port” and “left” both have four letters.)

Pressure-Treated (Wood): Wood (usually plywood) that has been infused with preservatives under pressure to resist rot and decay. Many pontoon boat decks are made of pressure-treated plywood for longevity, since it’s exposed to water and weather. The chemicals (like copper-based compounds) prevent fungus and rot from destroying the wood over time.

Propeller: Often shortened to “prop,” this is the rotating fan-like blade under the water that pushes the boat. The propeller is turned by the engine’s power and creates thrust by accelerating water backward. Outboard engines on pontoons typically have a three-blade or four-blade metal propeller. Choosing the right size and pitch prop is important for the pontoon’s performance.

R

Rails: The frame structure running around the edge of a pontoon boat’s deck, onto which the fence panels are attached. The rails (usually aluminum) form the top and bottom supports of the fence. They also serve as attachment points for things like cleats, bimini tops, and mooring covers. In simple terms, the rails are the skeleton of the pontoon’s sidewalls.

Right-of-Way: The priority to proceed afforded to one vessel over another in a crossing, meeting, or overtaking situation. In boating “right-of-way” is informally used to describe who should hold course (stand-on) and who should yield (give-way) under navigation rules. For example, a pontoon approaching another boat on its starboard side must yield, as the other boat has the right-of-way. Knowing the rules of the road prevents collisions.

Rub Rail: A protective strip running along the outer edge of a boat, usually where the hull or deck meets the sides. On a pontoon, the rub rail is often a vinyl or rubber insert in an aluminum channel along the perimeter of the deck. Its purpose is to take the abrasion if the boat rubs against a dock or another object, preventing damage to the fence or deck structure.

Rudder: A flat, vertical steering board or blade at the stern of a boat, used to turn the vessel by deflecting water flow. Pontoon boats typically don’t have a separate rudder – the outboard motor and its turning propeller serve the function of a rudder. However, if someone refers to rudder on a pontoon, they mean the motor’s lower unit and prop that steer the boat. (On sailboats or ships, the rudder is a distinct part controlled by a wheel or tiller.)

S

Skeg: A fin-like projection on the bottom portion of an outboard or stern drive’s lower unit. It’s the small keel fin just aft of the propeller. The skeg helps protect the prop from underwater impacts (it often hits first, saving the prop) and aids in keeping the boat tracking straight. If you strike a rock with the motor, the skeg may chip – it’s essentially a sacrificial piece to an extent.

Ski Tow Bar: A mounted metal bar or frame at the stern of a pontoon boat used for attaching tow ropes for watersports. Pontoons equipped for tubing, water skiing, or wakeboarding often have a ski tow bar (also called a tow pylon or sports bar) that elevates the tow rope above the outboard motor. This provides a better pull angle and keeps the rope clear of the engine.

Skipper: A casual term for the person in charge of the boat – the captain. If you’re the skipper of a pontoon, you are the one steering and making decisions for safe operation. It implies responsibility for the vessel and passengers. (Everyone should listen to the skipper’s instructions for safety.)

Slip: A parking spot for a boat at a marina or dock, usually one space along a pier or between two piers. A slip often has two parallel docks, and you maneuver the boat between them to dock. For example, you might rent a slip for your pontoon for the summer at a marina, meaning you have an assigned berth to tie up the boat whenever you’re not using it.

Stability: The quality of a boat that resists tipping or rolling. Pontoon boats are known for high stability because of their wide stance and buoyant tubes. Stability means the boat stays level even when weight shifts or waves hit. Good stability is why you can walk around on a pontoon without it rocking dramatically. (Excessive weight on one side can still overcome that stability, causing a list, but generally pontoons are very steady.)

Starboard: The right-hand side of a boat when facing forward (toward the bow). It’s the opposite of port. Starboard is indicated with a green light at night. For example, the starboard pontoon tube is the tube on the right side of the boat. In navigation rules, a boat on your starboard side has right-of-way in many cases.

Stern: The back end of the boat. On a pontoon, the stern area is where the motor is mounted, and often where boarding ladders or rear swim platforms are located. Stern is the opposite of bow. Many pontoons have rear seating or sun loungers in the stern as well.

Stern Drive (Inboard/Outboard): A propulsion system also known as an I/O (inboard-outboard), where the engine is mounted inside the boat’s stern and connects to an outdrive unit on the transom. It combines features of inboards and outboards. While not very common on modern pontoon boats (outboards are far more popular), a stern drive pontoon has an automotive-style engine inside and a drive unit with propeller outside. The entire external unit pivots for steering, similar to an outboard.

Strakes: Long, often triangular, metal strips attached along the bottom or sides of pontoon tubes. Known as lifting strakes, these help the pontoon boat perform better at speed. They provide additional lift (to assist with planing) and help channel water, improving handling and stability when turning. Pontoons with strakes can often go faster and ride higher than those without.

Substructure: The framework underneath the deck of a pontoon boat. It includes the crossbeams and support brackets that tie the pontoon logs together and hold up the deck (like floor joists under a floor). The substructure gives the boat rigidity. On a well-built pontoon, the substructure distributes weight across the logs and contributes to the overall strength of the vessel.

Swim Platform: A platform (or area) on a boat designed to make it easy to get in and out of the water. Many pontoons have a small swim platform at the stern – essentially an extension of the deck near the waterline, often where the boarding ladder is mounted. It gives swimmers a spot to sit or stand when coming out of the water before fully climbing aboard, and a place to prepare for entering the water.

T

Throttle: The control lever that adjusts the engine’s power and speed. On a pontoon boat, the throttle is usually a lever at the helm console that you push forward to go faster (forward gear) or pull back for reverse or idle. It regulates how much fuel/air mix goes to the engine, thus controlling RPM. Throttle controls are often combined with the gear shift in one unit (forward, neutral, reverse).

Tiller: A handle attached directly to the rudder or outboard motor used for steering. Small outboard engines often have a tiller handle instead of a wheel. While most pontoon boats have wheel steering, a tiny one with a very small outboard might be tiller-steered. In general boating terms, “tiller” is used when you physically push or pull a lever to turn the boat (common in small fishing boats, dinghies, or sailboats).

Trailer: A wheeled platform used to transport a boat over land. A pontoon trailer typically has two long bunks (carpeted support boards) or multiple support brackets shaped to fit the pontoon logs, and often a guide-on system to help center the boat when loading. Pontoons are often hauled on a dual-axle trailer due to their width and weight. Key parts of a trailer include the winch (to pull the boat up), tongue (hitch area), tires, and lighting.

Transducer: An electronic sensor device mounted on the bottom of a boat (or on the transom) that sends and receives sonar signals for depth finders/fish finders. The transducer emits sound pulses into the water and listens for echoes to determine depth or find fish. It often looks like a small puck or bar and is located near the stern of a pontoon, below the waterline. If your fish finder isn’t reading, checking the transducer placement or connection is a first step.

Transom: The flat back panel of a boat’s hull where an outboard engine is mounted. On a pontoon boat, the transom is usually part of the motor pod or a reinforced frame at the stern between the two tubes, strong enough to hold the engine’s weight and thrust. You’ll find the engine bolted to the transom. The transom may also have the boat’s HIN (ID number) and attachments like the ladder or fuel fitting.

Trim: Adjusting the angle of the boat’s propulsion or the boat’s attitude in the water. Typically, “to trim” on a pontoon means using the power trim on the outboard motor to tilt the engine up or down. Trimming the motor affects how the bow rides (down or up) and can improve efficiency and comfort. Proper trim can help a pontoon ride smoother and avoid the bow plowing water. (Trimming “down” means lower motor angle, keeping bow down; trimming “up” lifts the bow.)

Tritoon: A nickname for a triple-tube pontoon boat (tri = three). Unlike a standard pontoon with two logs, a tritoon has three pontoon logs under the deck. This design increases load capacity, stability, and often allows for higher horsepower engines (better performance). Tritoons can handle rougher water a bit better and usually turn more responsively due to that center tube.

U

Underskin: A flat sheeting (often aluminum panels) attached to the underside of a pontoon boat’s deck, covering the open framework between the tubes. Underskinning reduces drag and turbulence by preventing water from lapping against crossbeams and the bottom of the deck at speed. It also protects wiring and the wooden deck from spray. Many performance pontoons have underskin to improve efficiency and ride smoothness.

Underway: A term meaning the boat is not anchored, moored, or docked – it is in motion on the water. A pontoon is considered underway as soon as it’s drifting or powered in the water (even if just idling). In navigation rules, when you are underway you must exhibit proper lights at night and follow “rules of the road.” (If you start the engine and cast off lines, your pontoon is underway even before you throttle up.)

V

Vessel: A general term for any kind of watercraft. A pontoon boat is a vessel. In the context of rules and regulations, “vessel” can mean everything from a kayak to a large ship. For example, the Coast Guard might refer to your pontoon as a vessel in their language. It’s essentially the formal word for boat or ship.

VHF Radio: See Marine Radio. (VHF stands for Very High Frequency.) It is the primary means of short-range communication on the water. Pontoons that venture onto big water or coastal areas often carry a VHF radio to communicate with marinas, bridges, or in case of emergency. Common channels include Channel 16 (distress and calling) and various channels for boaters to chat or for authorities to broadcast information.

V-hull: A type of boat hull that is V-shaped in cross-section, common in speedboats, runabouts, or fishing boats. V-hull boats have a single hull that comes to a keel line (forming a “V” shape) to cut through waves. This is in contrast to a pontoon’s flat deck atop round tubes. Knowing the difference: a V-hull can handle chop by slicing through waves, whereas a pontoon relies on its wide footprint for stability. (Some hybrid pontoons have a partial V shape on center logs, but generally “V-hull” refers to traditional monohull boats.)

W

Wake: The wave pattern created in the water by a moving boat. A pontoon boat, when driven through the water, leaves a wake behind it (turbulence and waves spreading out from the stern). Large wakes can be hazardous to other small boats or cause shoreline erosion, which is why there are no-wake zones. As a courtesy, pontoon drivers slow down near others to minimize their wake.

Waterline: The level at which a boat floats in the water—the line where the water’s surface meets the hull. On a pontoon, you can usually see a slight discoloration or mark on the tubes where the usual waterline is. Everything below the waterline stays submerged when loaded normally. It’s important for weight distribution; too much weight and the waterline rises (boat sits deeper), which can affect performance.

Winch: A mechanical device with a crank or motor used for pulling or lifting heavy loads. In boating, a common example is the trailer winch—a hand-cranked or electric reel with a strap/cable at the front of a trailer used to pull the pontoon boat up onto the trailer. Another example is an anchor winch (or windlass) used to raise an anchor. Winches provide mechanical advantage, making it easier to haul weight by cranking a handle.

Winterize: The process of preparing a boat for winter storage. To winterize a pontoon typically involves: adding fuel stabilizer to the gas tank, running antifreeze through the engine’s cooling system if it’s an inboard or stern drive (outboards are usually just drained of water), changing the engine oil/lower unit gear lube, removing or charging batteries, and covering the boat. This maintenance routine prevents freeze damage and keeps the pontoon in good shape during cold months when it’s not in use.

Y

Yaw: The side-to-side swiveling motion of a boat’s bow, i.e., rotation around the boat’s vertical axis. If a pontoon is moving and its bow swings or wanders left and right off course, that is yaw. Good steering and proper weight balance minimize unwanted yawing. In simpler terms, yaw is the boat’s turning movement (as opposed to the boat’s roll or pitch). Excessive yaw can make steering feel loose, while a stable boat will hold a straight line with minimal yaw motion.