Boarding Ladder Buying Guide: Step Count, Mounts and Reboarding Safety
Quick answer: Pick a boarding ladder that puts at least 2 to 3 steps below the waterline, so the bottom step sits roughly 20 to 24 inches under the surface where a swimmer can get a knee or foot on it. Most outboard and stern-drive boats need a 3 to 4 step transom or swim platform ladder, and higher-freeboard boats need 4 to 5 steps. Choose stainless steel or anodized aluminum with wide non-slip treads, and make sure a person in the water can deploy it without help.
A boarding ladder looks like a convenience item until someone falls overboard, is too tired to climb, or is alone in the water with nobody on deck. At that point it is safety equipment. ABYC standards call for a reboarding means on recreational boats that a person in the water can reach and use unaided. This guide covers step count, mount styles, materials and the emergency ladders that fill the gaps.
Step 1: Measure your freeboard
Measure from the waterline to the top of the transom or swim platform where the ladder will mount. Then add the depth you want below water. A ladder that ends at the waterline is close to useless: a swimmer cannot step up onto a rung that sits at the surface.
| Mount height above waterline | Typical step count | Ladder type |
|---|---|---|
| Swim platform, under 12 in | 2 to 3 steps | Telescoping platform ladder |
| 12 to 24 in | 3 to 4 steps | Telescoping or folding transom ladder |
| 24 to 36 in | 4 to 5 steps | Long telescoping or side-mount ladder |
| Over 36 in, or no platform | 5 steps or more | Gunwale hook ladder or portable folding ladder |
Step spacing is usually 10 to 12 inches, so each extra step adds roughly a foot of reach. When in doubt, go one step longer.
Step 2: Choose the mount style
- Swim platform, telescoping: collapses flat on the platform and slides out into the water. The most common choice on bowriders, cruisers and pontoons.
- Transom, folding or telescoping: mounts to the transom of boats without a platform. Keep it clear of the propeller and trim tabs.
- Engine or jack plate mount: a compact flip-down step on the outboard bracket or jack plate. Popular on bass and bay boats with no room elsewhere.
- Gunwale hook or side mount: hooks over the gunwale for boarding from the side, useful on sailboats and when swimming away from the motor.
- Portable folding or rope ladder: clips to a cleat, rail or stanchion. A great backup and a must on boats that have no fixed ladder.
Step 3: Pick materials and treads
- 304 or 316 stainless steel: strong and corrosion resistant. 316 holds up better in salt water.
- Anodized aluminum: lighter and corrosion resistant when anodized, common on jack plate and dock ladders.
- Treads: wide, textured plastic or rubber treads are easier on bare feet and provide grip when wet.
- Look for at least 1 inch diameter tubing on fixed ladders and a published weight rating that covers your heaviest crew member.
Step 4: Make it usable from the water
This is the part most owners miss. A swim platform ladder stowed under a strap that only someone on deck can release does not help a person alone in the water. Choose a ladder with a release that can be reached from the water, add a pull lanyard, or keep a portable ladder rigged on long solo trips. Add a grab handle or rail at the top so the climber has something solid to pull on as they step aboard.
Step 5: Install it safely
- Through-bolt with backing plates and seal every hole with marine sealant. Platform loads are high when someone climbs with wet gear.
- Keep the ladder well clear of the propeller. Always shut the engine off before anyone uses the ladder.
- Check that the ladder locks securely when stowed so it does not rattle loose or deploy underway.
Common boarding ladder mistakes
- Too few steps, leaving the bottom rung at the waterline.
- No way to deploy it from the water.
- Mounted next to the propeller or a running outboard.
- Undersized hardware without backing plates, which cracks gelcoat.
- Relying on a dock ladder instead of carrying a reboarding means aboard.
Our picks by boat type
All in stock at Boat Supplies Direct.
Swim platforms
Whitecap 4-Step Telescoping Swim Ladder: 304 stainless with plastic treads, extends to about 45-3/4 inches and collapses to 15-1/2 inches on the platform.
Outboard boats without a platform
T-H Marine Twist Step Emergency Ladder mounts to the engine bracket or jack plate and rotates down when needed, or the Whitecap Teak Swim Platform with 2-Step Ladder to add a platform and ladder together.
Portable and emergency ladders
Sea-Dog 3 Step Folding Ladder or the Sea-Dog 5 Step Folding Ladder, with high-visibility orange steps that secure to a cleat, rail or stanchion, plus the Attwood 5-Step Rope Ladder with hooks for the gunwale.
Ladder hardware
Sea-Dog Chrome Brass Ladder Lock to keep a folding ladder secure when stowed.
Docks
Dock Edge 5-Step Aluminum Dock Ladder or the Dock Edge 4-Step Flip-Up Dock Ladder for getting out of the water at your slip.
Shop all boarding and dock ladders →
For the rest of your recovery plan, see our man overboard gear guide.
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Frequently Asked Questions
How many steps should a boarding ladder have?
Enough to put at least 2 to 3 steps below the waterline. Most swim platforms need 3 to 4 steps, and higher transoms or gunwales need 4 to 5 or more.
How far below the water should a boat ladder go?
Aim for the bottom step about 20 to 24 inches below the surface. That lets a swimmer get a knee or foot on it and stand up instead of doing a pull-up.
Is a boarding ladder required on a boat?
Coast Guard carriage rules generally do not list a boarding ladder for recreational boats, but ABYC standards call for a reboarding means that can be used from the water, and many builders follow them. Check current USCG rules and your state's requirements.
What is the best boarding ladder for a boat without a swim platform?
A transom ladder, an engine or jack plate step ladder, or a gunwale hook ladder. Portable folding ladders are a good backup on any boat.
Stainless steel or aluminum boat ladder?
Stainless is stronger and the standard for fixed salt water ladders. Anodized aluminum is lighter and corrosion resistant, which suits jack plate steps and dock ladders.
Can a person in the water lower my swim ladder?
Only if it is designed for it. Check that the release can be reached from the water, add a pull lanyard if needed, or carry a portable ladder for solo trips.
This guide is general information. Follow ABYC standards, your boat builder's guidance and the ladder manufacturer's installation and weight rating instructions, and always shut down the engine before anyone uses a boarding ladder.
