All A(re)board

Author: Frank Lanier

There’s only one thing better than hopping into the water for a swim while anchored in that secluded cove — being able to get back on board when you’re done. Most every boater has heard at least one tale at the yacht club Tiki bar about a vessel’s crew rushing to hit the water, only to dis- cover they’d forgotten to deploy a swim ladder and were unable to climb back on board. In an effort to keep you from becoming fodder for such tales, here’s the scoop on choosing and installing a boarding ladder.

What They Do

Boarding ladders provide a means for swimmers, skiers, etc., to safely enter and exit the water from either a boat’s deck or swim platform. They can also make it easier to board a dinghy and can assist in a man-over- board situation in calmer waters.

American Boat and Yacht Council (ABYC) standards state all boats must have a means of unassisted reboarding that is accessible to or deployable by a person in the water. To make boarding easier, the top surface of the lowest step of the ladder should extend at least 12 inches below the waterline with the boat in a static floating position.


Boarding ladders can be fixed or portable, and they come in a variety of styles and prices. Select those con- structed of non-corroding materials, such as plastic, aluminum or stainless steel (aluminum weighs less and is cheaper than stainless steel, although stainless steel is stronger and more durable).


Portable ladders are just that — removable ladders that are normally stowed until needed. The most com- mon type found aboard smaller powerboats is the portable gunwale- mount unit that simply hooks over the side of the boat. Gunwale-mount- ed ladders are handy and relatively inexpensive (one reason for their popularity); however, they can be flimsy. Another possible downside is that they tend to move when in use, making them harder for grain-fed members of the crew to climb.

Removable ladders (as opposed to portable ladders) are attached using permanently mounted brackets (typi- cally bolted to the gunnels or deck of a vessel) and utilize keyhole slots, cot- ter pins or some similar arrangement that allows them to be easily installed and removed when not in use. Some units are rigid one-piece units, while others are hinged (so that they can be folded up rather than removed when not in use), telescoping, or even accordion-style units, which can be adjusted to facilitate boarding a dinghy or fully extended for water entry or exit.

Swim-step ladders are typically mounted to a boat’s swim platform, while swim-platform ladders (essen- tially a small fixed step with a folding ladder attached) are an option for vessels lacking the room for a full swim platform (e.g., outboard-pow- ered boats). When not in use, they normally fold up onto the swim plat- form or telescope out of the way.

Installation of Swim- Platform Boarding Ladder

Although the thought of drilling holes in your boat can be unnerving at first, installing a boarding ladder is well within the ability of most DIYers. Here are the basic steps for installing a typical swim-platform ladder.

1 Review the manufacturer’s instructions thoroughly.

2 Select the best side of the transom to mount the ladder. The side you choose should provide easy boarding and not interfere with previously mounted equipment. The starboard side is preferable on most boats, because the captain can see people boarding more easily.

3 Stern ladders should be mounted as far as practical from the boat’s centerline (and propellers). Turn the out- board or stern drive as far as possible toward the selected side, then mark the transom with a grease pencil to show how far the unit extends. Next, position the swim step outboard of the above mark, keeping it above and parallel with the waterline. The exact height above the waterline called for by the manufacturer may vary, but 6 inches is a good general rule if not provided.

4 Mark the holes for the mounting bolts with a grease pencil. Verify you’ll be able to access each from the inside once drilled (in order to install and tighten the mounting hardware) and that you won’t be drilling into any- thing such as equipment, wire runs, plumbing, etc.


5 Drill the holes using appropriately sized bits. Start by making an indentation at the center of each hole with an ice pick or other suitably sharp object (to prevent your drill bit from wandering). Next, drill a small pilot hole, then re-drill with the correct- sized bit. To avoid chipping the gel- coat, use sharp bits and drill at slow speed using minimal pressure on the drill — allow the bit to do the work. Another trick is running the bit in reverse until through the gel coat, then switching to forward and continuing to drill as normal.


6 Dry mount the ladder to verify everything is properly aligned, then remove the ladder and thoroughly seal the edges of any exposed coring with epoxy (to prevent water intrusion into the transom).


7 Once the epoxy has dried, install the ladder, thoroughly bedding (caulking) the mounting hardware with a suitable marine-grade sealant. Use only marine-grade stainless steel mounting hardware, and install backing plates or large washers to spread the load evenly.

8 Check and tighten the mounting hardware periodically.


Additional Considerations
For stern-mounted ladders, place a warning sticker about propellers and CO (carbon monoxide) poisoning at the helm, as well as a second decal warning about CO, propellers and the dangers of teak surfing on the exterior of the stern or transom. 


Your email address will not be published. Required fields are marked *