Nautical terms
32 of 469 terms in Anchoring & mooring. Show all
A
- Anchor Anchoring & mooring
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A device that digs into or grips the bottom so that, through its resistance to being dragged, it holds a vessel within a limited area. Types suit different bottoms; many boats carry two of different styles.
Federal law does not require an anchor on a recreational boat, but BoatUS Foundation recommends one big enough to hold the boat overnight, and the Coast Guard boat crew handbook advises carrying two.
dco.uscg.mil · higherlogicdownload.s3.amazonaws.com · boatus.org · uscgboating.org
- Anchor bridle (Bridle) Anchoring & mooring
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Two snubber lines joined at the anchor chain and led to cleats on each side of the bow (or hulls of a catamaran). Like a snubber it absorbs shock loads, and it also reduces the boat's tendency to swing back and forth at anchor.
In towing, "bridle" also means a two-legged line spreading a tow's load across two fittings.
- Anchor chain (Proof coil, BBB chain, High-test chain) Anchoring & mooring
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Galvanized steel chain used alone or with nylon line in a rode. Common grades are proof coil (general use), BBB (shorter, thicker links, often used with windlasses) and high-test (hardened, stronger and lighter).
- Anchorage area (Anchorage, Special anchorage area) Anchoring & mooring
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A customary or officially designated area where vessels may anchor, shown on charts. In Coast Guard special anchorage areas, vessels under 20 m need not show anchor lights or sound anchor signals.
higherlogicdownload.s3.amazonaws.com · navcen.uscg.gov · oceanservice.noaa.gov
B
- Bow roller (Anchor roller) Anchoring & mooring
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The roller fitting at the bow over which the anchor rode runs and where many boats stow the anchor. Measure scope from the height of the roller, not from the water surface.
C
- Capstan (Rope drum, Warping drum) Anchoring & mooring
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The smooth drum on a windlass used for hauling rope, such as a rope rode or a dock line, by taking turns around it.
- Catenary Anchoring & mooring
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The natural sag in an anchor chain or rode caused by its own weight. The sag acts like a spring and keeps the pull on the anchor low; in strong winds the chain straightens and that cushioning is lost.
higherlogicdownload.s3.amazonaws.com · practical-sailor.com · vikinganchors.com
- Chain stopper (Chain compressor, Chain lock) Anchoring & mooring
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A fitting between the windlass and the bow roller that grips the anchor chain and takes the load off the windlass once the anchor is down or stowed.
- Claw anchor (Bruce anchor) Anchoring & mooring
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A one-piece anchor with a scoop of claws that lets the boat swing all the way round without breaking the anchor out. It performs much like a plow anchor at a lower weight.
D
- Dragging (Dragging anchor) Anchoring & mooring
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When the anchor fails to hold and slides across the bottom, letting the boat drift. Signs include bearings or ranges to shore changing while the boat should only be swinging.
F
- Fluke (Flukes) Anchoring & mooring
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The flat, pointed parts of an anchor that dig into the bottom and give it holding power.
- Fluke anchor (Danforth anchor, Lightweight anchor) Anchoring & mooring
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A lightweight anchor with two long, flat, pivoting flukes that bury in the bottom. It holds very well for its weight and works best in hard sand or mud.
G
- Ground tackle Anchoring & mooring
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All the gear used to anchor: the anchor, its chain and line (the rode), and the shackles, swivels and fittings that join them and fasten them to the boat.
- Gypsy (Wildcat, Chainwheel) Anchoring & mooring
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The windlass wheel with shaped pockets that grip the chain links as it hauls or lets out the rode. Each gypsy fits one chain size, and some are made to handle both rope and chain.
Replacement chain must be the size the gypsy is made for.
H
- Holding ground (Bottom type) Anchoring & mooring
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How well the bottom holds an anchor. The Coast Guard handbook rates firm sand and dense clay as excellent, sticky mud good, soft mud or loose sand fair or questionable, and rock, coral and grass as poor. Charts show bottom type.
L
- Lunch hook Anchoring & mooring
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A small, light anchor for brief stops in calm weather, such as lunch or a swim, carried in addition to a larger working anchor.
M
- Mooring (Mooring ball, Mooring buoy) Anchoring & mooring
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A permanent anchor or screw on the bottom, with chain up to a floating buoy that boats tie to. Mooring buoys are white with a blue horizontal band and are the only buoys you may legally tie up to.
Use only a mooring you are permitted to use; public ones are usually rented from the harbormaster, who can tell you the size limit.
boatus.org · higherlogicdownload.s3.amazonaws.com · boatus.com · navcen.uscg.gov
- Mooring pennant (Pennant, Mooring line) Anchoring & mooring
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The short, strong line from the mooring buoy that you bring aboard and make fast to your bow cleat or post. Watch for chafe where it crosses the boat.
- Mousing (Moused shackle, Seizing) Anchoring & mooring
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Wrapping a shackle pin (or hook opening) with wire or small line so it cannot unscrew or come open. The Coast Guard handbook advises seizing anchor shackle pins, noting that many anchors have been lost through poorly attached rodes.
- Mushroom anchor Anchoring & mooring
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A round, bowl-shaped anchor named for its mushroom shape. Large ones weighing up to several thousand pounds are widely used to hold permanent moorings.
P
- Pickup buoy (Pickup float, Whip) Anchoring & mooring
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The small float on the end of a mooring pennant (sometimes with a stiff whip) that you grab with a boat hook to bring the pennant aboard.
Approach a mooring from downwind (or down-current), slowly, and stop the boat as the pickup comes alongside the bow.
- Plow anchor (CQR, Delta anchor, Plough anchor) Anchoring & mooring
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An anchor shaped like a farm plow, with a fixed or hinged shank, that turns over and buries itself when pulled. A common choice for cruising boats; it holds in many bottoms and resets fairly easily when the boat swings.
R
- Rode (Anchor rode, Anchor line) Anchoring & mooring
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The line, chain or combination of both that connects the anchor to the boat. Nylon three-strand is the usual choice for rope rodes because it stretches to absorb shock; a length of chain at the anchor end lowers the angle of pull and resists chafe.
Markers along the rode show how much is out, which helps you set the right scope.
higherlogicdownload.s3.amazonaws.com · maxwellmarine.com · boatus.org
S
- Scope (Anchor scope) Anchoring & mooring
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The ratio of rode let out to the height from the bottom up to the bow roller or chock (water depth plus bow height, not depth alone). Enough scope keeps the pull on the anchor near horizontal so it digs in rather than lifting out.
Guidance from the Coast Guard and BoatUS: 5:1 as a minimum in good conditions, 7:1 where you have room or for overnight. Example: 10 ft of water plus 4 ft of bow height at 7:1 is 98 ft of rode. Add more as wind rises.
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- Setting the anchor (Setting the hook) Anchoring & mooring
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Getting the anchor dug in: lower it (don't throw it) while the boat drifts or backs slowly, pay out rode, snub it to let the anchor bite, then back gently to confirm it holds before settling in.
Approach the spot heading into wind or current. Taking two bearings or a natural range right after anchoring lets you check later whether you are dragging.
- Shackle (Anchor shackle) Anchoring & mooring
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A U-shaped metal fitting closed with a screw pin, used to join chain, anchor, swivel and thimble. On anchor gear the pin should be moused (wired) so it cannot work loose.
- Shank Anchoring & mooring
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The long main bar of an anchor, to which the rode is attached at one end and the flukes at the other.
- Snubber (Snubbing line, Anchor snubber) Anchoring & mooring
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A length of stretchy nylon line attached to an all-chain rode with a chain hook or hitch and led to a bow cleat, so it absorbs sudden jerks and takes the load off the windlass.
Practical Sailor found nylon (or a longer polyester line) works best and recommends chafe guards and a spare; snubbers can fail without warning, so the chain should also be secured with a chain lock or stopper.
- Swing radius (Swing area, Swinging room) Anchoring & mooring
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The circle your boat can sweep around its anchor as wind and current change. Never drop anchor inside another boat's swing area.
Different boats ride to their anchors differently, so the Coast Guard handbook and BoatUS advise leaving plenty of room.
- Swivel (Anchor swivel) Anchoring & mooring
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A fitting in the ground tackle that lets the boat turn around its anchor without twisting the chain or line.
W
- Weigh anchor (Hauling, Anchors aweigh) Anchoring & mooring
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To raise the anchor off the bottom and bring it aboard, by hand or with the windlass.
- Windlass (Anchor windlass, Anchor winch) Anchoring & mooring
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The winch at the bow, manual or powered, that raises and lowers the anchor rode. It may be horizontal or vertical and usually has a gypsy for chain and a capstan drum for rope.
The maker's normal working load is typically a fraction of its maximum pull; don't use the windlass to hold the boat at anchor, use a chain stopper or snubber.
General guidance for recreational boaters, researched from the sources listed and written in our own words. Your equipment manuals, local knowledge, the Navigation Rules and a qualified instructor come first.