Boat Cleat Buying Guide: What Size Cleat You Need and How to Mount It
Quick answer: Size a boat cleat at roughly 1 inch of cleat length for every 1/16 inch of line diameter, so 3/8 inch dock line wants a 6 inch cleat and 1/2 inch line wants an 8 inch cleat. Pick stainless steel for anything that takes real load, and always through-bolt it with a backing plate. Screws alone will pull out the first time the boat surges in a wake.
Cleats look simple, but they carry every load your boat puts on its dock lines: wind, current, passing wakes and the occasional bad landing. An undersized cleat makes it hard to get a proper wrap of line on it, and a poorly mounted one can tear out of the deck and take a chunk of fiberglass with it. This guide covers sizing, materials, cleat styles and the install details that keep them where they belong.
Step 1: Size the cleat to your line
The rule of thumb is 1 inch of cleat for every 1/16 inch of line diameter. That leaves room for a full turn plus a figure-eight and a locking hitch. A cleat that is too small for the line forces you to jam on half a wrap, which slips.
| Boat length | Typical dock line | Cleat length |
|---|---|---|
| Up to 20 ft | 3/8 inch | 6 inch |
| 20 to 30 ft | 1/2 inch | 8 inch |
| 30 to 40 ft | 5/8 inch | 10 inch |
| 40 ft and up | 3/4 inch or more | 12 inch or larger |
If you are between sizes, go bigger. A larger cleat also handles two lines at once, which happens more often than you think when you add spring lines or raft up.
Step 2: Choose the material
- 316 stainless steel: strongest and most corrosion resistant. The right choice for bow, stern and spring cleats on the boat.
- Chrome-plated zinc: good looking and affordable for lighter boats and accessory cleats, but the plating can pit in salt over time.
- Aluminum: light and common on docks and pontoons.
- Galvanized steel: the workhorse for dock cleats. Rugged and inexpensive, not meant for the boat itself.
- Nylon: fine for small craft, fender lines and light-duty use only.
Step 3: Pick a style
- Open base (horn) cleat: the standard. The open base lets you pass an eye splice through it, which is handy.
- Hollow base cleat: stronger base design for heavy loads and larger boats.
- Pull-up and pop-up cleats: retract flush with the deck so nothing snags lines, legs or fishing line. Popular on center consoles and bow decks.
- Flip-up dock cleats: fold flat on the dock so nobody trips over them.
- Cam and V-cleats: for sailboat running rigging, not dock lines.
Step 4: Mount it so it stays
Docking loads are sudden and large. A boat surging in a wake can shock-load a cleat many times its static weight.
- Through-bolt every cleat with stainless machine screws or bolts, never wood screws into fiberglass.
- Add a backing plate under the deck (aluminum, stainless, or thick fiberglass or G10) larger than the cleat base so the load spreads out.
- Seal every hole with marine sealant, and on cored decks seal the core with epoxy first so water cannot rot it.
- Orient it right. Angle the cleat about 15 degrees off the line of pull so the line wraps cleanly without fouling.
Step 5: Tie off correctly
Lead the line to the far horn first, take a full turn around the base, make one or two figure-eights across the top, then finish with a half hitch (locking turn). Extra wraps do not add holding power, they just make it harder to cast off.
Common cleat mistakes to avoid
- Too small for the line. If you cannot get a full turn and a figure-eight on it, the cleat is undersized. Size up rather than downsizing your line.
- Screws instead of bolts. Wood screws in fiberglass hold until the first hard surge, then pull straight out of the deck.
- No backing plate. Washers alone concentrate load on a small area and can crack the deck around the cleat.
- Unsealed holes in a cored deck. Water wicks into balsa or foam core and rots it from the inside, which is an expensive repair.
- Too few cleats. Most boats need at least bow, stern and midship (spring line) cleats on each side to dock properly in wind and current.
- Mixing metals carelessly. Use stainless fasteners with stainless cleats, and isolate dissimilar metals where they meet aluminum.
Check your cleats every season. Look for cracks in the gelcoat around the base, rust weeping from fasteners, and any movement when you pull hard on the horn. Any of those means it is time to re-bed or re-mount.
Our picks by job
All in stock at Boat Supplies Direct.
Heavy-duty bow and stern cleats
Whitecap Heavy Duty Hollow Base Stainless Cleat, 8 in or the 12 inch version for larger boats.
Everyday boat cleats
Perko 6 in Open Base Cleat or the Perko 8 in Open Base Cleat.
Flush decks with nothing to snag
Whitecap Pull Up Stainless Cleat, 6 in or the Whitecap E-Z Push Up Stainless Cleat.
Dock cleats
Whitecap Galvanized Dock Cleat, 10 in, the low-profile Dock Edge Flip Up Dock Cleat, 8 in, or the Dock Edge Solar 10 in Aluminum Dock Cleat that lights up at night.
Fender lines
Whitecap 2 in Fender Cleat. Pair it with properly sized fenders from our fender buying guide.
Frequently Asked Questions
What size cleat do I need for my boat?
Use about 1 inch of cleat length per 1/16 inch of line diameter. For 3/8 inch line, a 6 inch cleat. For 1/2 inch line, an 8 inch cleat. When in doubt, size up.
What size dock line goes with my cleat?
Work backward from the same rule. A 6 inch cleat suits 3/8 inch line, an 8 inch cleat suits 1/2 inch, and a 10 inch cleat suits 5/8 inch line.
How do you mount a cleat on a boat?
Through-bolt it with stainless hardware and a backing plate under the deck, seal the holes with marine sealant, and seal any exposed deck core with epoxy first.
Are stainless steel cleats better than chrome?
For working cleats in saltwater, yes. Stainless resists corrosion and carries more load. Chrome-plated zinc is fine for lighter duty and looks good, but the plating can pit over time.
What are pull-up cleats?
Cleats that retract flush into the deck when not in use, so lines, feet and fishing line do not catch on them. Pull one up when you need it.
How do you tie a boat to a cleat?
Take the line to the far horn, make a full turn around the base, cross over the top in one or two figure-eights, and finish with a locking half hitch.
This guide is general information. Follow your boat builder's recommendations for hardware placement and use a qualified technician if your deck is cored or you are unsure about backing.
