Boating and Fishing Dictionary

If you’re just getting into the world of boating and fishing, you probably hear conversations at the ramp or on TV with a few new words. Here’s a list of boating and fishing words so you can sound like you’ve been doing it your whole life.

Boat Terms

AFT

Toward the stern or back end of the boat.

ATHWARTSHIP(S)

Running in the direction across the boat or from side to side

BALLAST

Weight placed in a boat to influence trim.  Ballast can be lead, iron, concrete, etc., depending on the space available.

BASELINE

A baseline is a straight line from which you start your dimensions when laying out any project.

BATTENS

Thin semi-rigid strips of wood used to ensure fair lines and surfaces are built and maintained during the boat building process

BEAM

Width, generally the widest point on the hull, but beam could be given at any point in the hull.

BILGE

The lowest inner part of a boat’s hull.  The “open” parts of a vessel between the lowermost finished sections and the bottom.  Bilge water accumulates in the bilge. 

BIMINI

Sun shade. A bimini provides protection from the sun. It is commonly made from fabric mounted on a collapsible frame.

BOLSTER CUSHIONS

Cushions on the coaming – sometimes called Coaming Pads””

BOOT TOP

A painted line, just above the waterline.

BOW (as in bow-wow, not bow tie)

The front of the boat.

BOUNDRY BLOCK

The minimum size of a cube that will contain all the surfaces of an object.   Note that the size of the block can be influenced by orientation of the object.  In other words, the Boundry Block may become larger or smaller by rotating the object in any of the X, Y or Z axes

BULKHEAD

A vertical, athwartship partition, most often serving as a structural member of the “stringer grid”

BULWARK

An extension of the planking above the deck to form a rail.

BUTTOCK

Buttock lines are imaginary sections cut through the hull parallel to the boat’s centerline.  The 6” buttock is the imaginary line 6” outboard of the centerline

CAMBER

Athwartship curve of the vessel’s deck.

CATAMARAN

A vessel with two parallel hulls.

CAVITATION

Essentially, to suck air. This term is primarily used in conjunction with propellers and rudders. When cavitating, the propeller will speed up, but power is lost.  Webster’s Dictionary: “the formation of partial vacuums in a flowing liquid as a result of a separation of its parts”. i.e. aeration of the liquid.

CENTER CONSOLE

A boat where the helm (throttle and steering wheel) are located generally amidships and close to the centerline.   There is usually clear passage 360 degrees around the console.

CENTER OF LATERAL RESISTANCE (CLR)

The geometric center or pivot point of the underwater hull profile.

CHINE (Chine log)

The junction of the side and bottom surfaces

CLEAT

A T-shaped pieve of metal or wood to which lines (ropes) are attached. Or, a strip of wood or metal that is attached to one part of an object so another piece can be attached.

COCKPIT

“In small decked vessels, a sunken space toward the stern used by the helmsman.” …Webster’s New World Dictionary.
On a center console, the inside area could be called a cockpit, but this term is more often used to define a more limited area.

COAMING

A longitudinal member at the cockpit perimeter.

DAVITS

Curved uprights projecting over the side of larger boats for suspending or raising and lowering a smaller boat.

DEAD-RISE

Looking at the hull in cross section, the angle the bottom rises from a horizontal. The smaller the deadrise the flatter the bottom.  The deadrise increases towards the bow of the boat.

DEEP VEE

A hard chine power boat having a 15 degree or more angle deadrise at the transom.

DELTA

On planning hulls it is the aft section of the running surface.   It is the part of the hull that has a constant section with straight buttock lines.   The image below shows the patent drawing associated with Harry Schoell’s patent granted in 1978.   The patent has since been abandoned but the delta aft section is often incorporated in running surfaces developed today.

DISPLACEMENT HULL

A hull that will not exceed a fixed speed which increases with the length of the hull. Additional power will only allow a hull to maintain hull speed against a head wind or under load. (See PLANING HULL)

DRAFT

The depth of water a boat can travel over without hitting the bottom.

FAIR

A “fair” line is one with no dips, bumps, or irregularities.  Fair lines need not be straight.

FIDDLE

A frame or railing on a horizontal surface intended to keep things from falling off in rough weather.

FILLET

A fillet is a cove shape on an inside corner.

FLARE

When the sides of the boat go outboard as they rise.  If the sides of the boat come inboard as they rise it is called tumblehome

FRAMES

Athwartship members (ribs) of the hull framework.

FREEBOARD

The distance from the water to the sheer.

GARBOARD

The “plank” adjoining the keel at the aft most edge of the running surface. Garboard drain plugs are installed in the at the lowest point along the garboard.

GUNWALE (GUNNEL)

The upper edge of the side of a boat. Is frequently used interchangeably with SHEER.

HOOK (re. boat bottom)

This is one of two conditions in the bottom of a planing boat that can lead to performance problems. When the boat is right-side-up, the bottom curves up from the transom; is “dished” forward of the transom. This “hook” will drive the bow down, reducing performance. Can also lead to the bow “bobbing” up and down. The aft section of the hull, seen in profile, should be straight.

KEEL

The junction of the bottom planking along the centerline of the boat or the inside member backing this junction aft of the stem. The term also refers to an outer longitudinal appendage on the centerline. The purpose of this member is to keep the wind from blowing the boat sideways from its forward course. The keel also serves to protect the prop on a power boat.

KERF

The cut made by a saw blade.

KNEE

A brace or reinforcement between two joining planes. On our boat designs, knees are used to reinforce the junction between the bottom and the transom.

KNOT SPEED CONVERSION

To convert to miles per hour, use the following formula: speed in mph = speed in knots divided by 0.87.

KNUCKLE

An abrupt or hard edged change in the shape or curve of a surface – common at the hull to deck joint.

LEEWARD

On a hull, the side away from the direction of the wind; the protected side. In the days of sailing ship warfare, you wanted your opponent in your lee (to leeward) which took his wind and gave you the advantage.

LEEWAY

To drift from course in the direction of the wind.

LIFTING STRAKES

Longitudinal members running fore and aft on the outside bottom of the hull. The purpose is to stabilize and create lift on a deep vee hull when under power.

LIMBER

A hole or channel that allows water to drain to the lowest point in the hull. Limbers can be through longitudinal (stringers) or athwartships (bulkheads) structural members

LISTING

When a hull tilts to one side when sitting in the water. Can be caused by uneven loading of passengers or cargo.

LOA

Length Overall is measured from the forward most part of the boat to the aft most part of the boat – we do not include the engines in this measurement

LOFTING

Lofting is the process of drawing the hull lines full size from the designer’s scale drawings. The intersections of the contours of various horizontal and vertical sections are measured from an imaginary “base line” using an architect’s scale. These junctions are then laid out, point by point, in their full size. Because it is difficult to take accurate dimensions from a small drawing, it is necessary to adjust these lines to assure that they are “fair”. A listing of these points is called a table of offsets. It takes a lot of space to loft.

LONGITUDINALS

Those hull framing members that run the length of the boat (i.e. stringers, chine, keel, sheer, battens).

MOISTURE CONTENT

Weight of the water within a piece of lumber measured as a percentage of the weight of the dry wood. Typical moisture content for kiln dried construction lumber is 15%. Wood absorbs or gives off moisture depending on the ambient moisture in the air. The percentage of wood that is not moisture is referred to as “dry solids,” that is, dried construction lumber would be 85% dry solids. Product standards for lumber manufactured in the United States are developed under the jurisdiction of the U.S. Department of Commerce and administered by the American Lumber Standards Committee (ALSC). Members of the ALSC are representatives of various softwood lumber trade associations. As specified in the ALSC American Softwood Lumber Standard, softwood lumber is sold as “dry” if at a moisture content of 19% or less. Most hardwoods manufactured in the United States are produced to standards developed by the National Hardwood Lumber Association (NHLA). No single moisture content, however, is specified for hardwoods because the uses are more specialized. The moisture content must be specified by the buyer and agreed to by the seller; a 10% moisture content specification is common.

MONOCOQUE

A structure in which the outer covering (planking) carries all or a major part of the stresses.

MONOHEDRON – see DELTA

The ideal shape for planing over the water surface is one of constant (mono) section. Thus monohedron describes a hull that has a running surface of constant section; in practice the sections may not be exactly the same. See the definition of Delta above.   A Delta hull is a monohedron shape in the aft portion of the running surface.

MOTOR WELL

When an outboard motor is mounted on the transom, a motor well is a box-like structure in front of the motor that catches water that may wash over the transom .The well provides clearance for engine rigging and steering cylinders and allows the motor to tilt up

OFFSETS

Measurements supplied by a designer for the builder in order to lay down the lines of the hull.

OUTRIGGER

May refer to the lateral supports that attach floats to the main hull (outrigger canoe, catamaran or trimaran).   Or, on a fishing boat is is a pole that allows boats to troll more lines at a reduced risk of tangling.

P & S

Port and starboard (both sides). The port is the left side of a boat looking forward, starboard on the right.

PAINTER

A line made fast to the bow of a small boat.

PENANT

A pointed flag.

PITCH

Plunging forward, the rising and falling of the bow and stern of a boat; a fore and aft motion as opposed to roll.  (Propeller) The angle at which a propeller cuts through the water. Pitch is measured as the distance a propeller would move forward with a single rotation, if there was no resistance.

PLANING HULL

A hull that lifts and skims the surface of the water causing the stern wake to break clean from the transom. In practical terms, a planing hull has a speed potential limited only by weight and power.

PORT

Sitting in the boat facing forward the port side is the side on the left.

PRISMATIC COEFFICIENT

The ratio the hull displacement bears to the displacement of a shape which is the same length as the waterline length of the boat and has the same constant cross-sectional area as the greatest cross-sectional area the hull.

PULPIT

RABBET

A carpentry term. A cut or groove along or near the edge of a piece of wood that allows another piece to fit into it to form a joint. A dado.

RAKE

The fore or aft angle of anything from perpendicular.

REVERSE CHINE

A concave curve in the bottom at the chine. The usual purpose is to deflect spray.

RIGHTING MOMENT

A measure of the tendency of a boat to return to upright when heeled. It is a product of the distance between the centers of gravity and buoyancy and the total weight of the boat.

ROCKER (re. boat bottom)

This is one of two conditions in the bottom of a planing boat that can lead to performance problems. When the boat is right-side-up, the bottom curves up toward the transom. This will lead to “porpoising”. A similar effect will result from “rounding” the trailing bottom edge at the transom. In the extreme and/or at high speed, this can be dangerous. The cause is usually caused by allowing the transom to drop during construction. The aft section of the hull, seen in profile, should be straight. See HOOK

ROLL

Side to side motion on a boat as opposed to pitch, the fore and aft movement.

RUBRAIL

The vinyl and stainless strip installed at the boats perimeter to protect the boat from damage when it bumps into something.

SCARF

A joint in a board to make it longer – usually in the ratio of the joint is 7 times as long as it is high.  Longer is better

SCANTLINGS

The dimensions of a building material, especially the width and thickness of a timber. The dimensions of the structural parts of a vessel.

SHEER (Sheer clamp)

The junction of the hull side and deck. A boat with a “lot of sheer” is higher at the bow and stern than the center when viewed in profile; with little sheer, the sheer arc will be closer to a straight line (a hog sheer).

SHOAL

Shallow

SKEG

A longitudinal appendage on the outboard motor providing protection for the prop and helping with directional control.

SPEED-LENGTH RATIO

A formula used to compare potential speeds of displacement or semi-displacement hulls; not used for full planing hulls. Formula: Speed in knots=1.34 x square root of the waterline length.

SPREADER LIGHT

STARBOARD

When you are sitting in the boat facing the bow, starboard is on your right.

STEM

The junction of the planking at the forward end of a typical hull. The member to which the planking attaches at this junction.

STRAKES

See LIFTING STRAKES

TRANSOM

The member forming the aft (stern) end of the boat.

TUMBLEHOME

The top of the hull side (sheer) is closer to the centerline than the bottom of the hull side.  In non-boating terms a wine glass that has a smaller diameter at the top than towards the bottom has “tumblehome”.

VEE BOTTOM

When the hull bottom has a V shape athwartships.

WARP

Any variation from a true and plane surface. It includes bow, cup and twist and is often caused by irregular seasoning.

WATERLINE LENGTH

May be called DWL or LWL.  It is the distance from the intersection of the stem of the boat with the water to the intersection of transom or aft most section of the boat with the water. 

WINDWARD

Toward the direction from which the wind is coming. The windward side of a hull receives the force of the wind. The leeward side is the “calm& or protected side.

YAW

A vessel which will not hold a steady course, but swings from side to side of it, is said to yaw.

Fishing Terms

BAIL

Part of a spinning reel that flips up and down. It allows the line to free spool off of the reel or locks it so you can reel it in.

BRAID

A type of fishing line made up of little fibers. It has a smaller diameter than other options of the same strength which makes it cast better.

CIRCLE HOOK

A hook that is curved so the point faces inward. The idea is that a surface won’t get hooked unless it fits inside the circle, which is why you almost always hook the fish on the jaw when using these.

DRAG

The part of the reel that puts tension in the fishing line. The setting can be changed based on the situation or the line that has been paired with the reel.

JIG

(n) A J-hook with a weight on the front that is typically paired with a soft artificial bait to mimic bait. (v) The act of pulling up on a lure and then letting it sink before repeating the action.

SPOOL

The part of the reel that holds the fishing line.

J HOOK

The stand hook in the shape of a J. These used to be what everyone used but now they are typically just found on lures and jigs.

ROCK FISH

When you hook up to structure but keep reeling thinking it’s a fish. Usually due to the drag being set too low. Gets everyone really exciting until the captain starts laughing.

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