Allport Marine Survey, Steilacoom, Washington, USA - Tony Allport, SAMSŽ AMSŽ

Few things complement the pleasure of boating like a proper boarding ladder. For children, parents, and grandparents alike, a safe boarding experience gives the confidence that is fundamental to enjoying the anticipation and memories of fun on the water.

A boarding ladder also accommodates a critical need on every boat, which is to have a reliable means of recovering someone from the water. It is not an optional piece of equipment in my book and it deserves to be well considered and integrated into the design of a boat. With this in mind, I adapted a classic boarding ladder design and built it for my boat. It looks and works great and, while not necessarily perfect for all boats, the process might be adaptable to your needs.

Classic yacht boarding ladders can still be seen occasionally but they’re not readily available. My challenge was not to invent it but, rather, to adapt the concept for my boat.

Generally, this type of ladder is hung on metal brackets attached to the side of the hull or rail, but I have a 2-inch toerail molded into the deck edge that offers enough of a lip so it can be securely hooked on. I wanted to avoid using any kind of customized or hard-to-find hardware and also to keep the boat as clean and uncluttered as possible. I fashioned the ladder sides out of 3/4-inch marine plywood, carefully fitting them to the hull side and toerail in a hooked shape that resembles a candy cane. I chose plywood because it provides the needed cross-grain strength across the hooked portion.

Fitted to the gate

I chose to fit my ladder to the starboard quarter of the boat because that is where the gate in the lifelines is and we’re accustomed to boarding there. This involved a compromise, however. Given the rapidly changing hull shape at the ends of the boat, the two ladder legs have to be fitted to substantially different curves. This means that the ladder can only hang from this one place on the rail. If a ladder were to be fitted to the midship section of the hull where the shape is fairly consistent for a couple of feet, it might be interchangeable on either side of the boat. This could have the additional benefit of allowing the shrouds to be used as a handhold while climbing aboard.

marine surveys by Allport Marine Survey, Steilacoom, Washington, USA - Tony Allport, SAMSŽ AMSŽ

Once I had chosen the location, I had to make a pattern of the shape of the hull and rail at that point. I used 4 x 5 file cards, a stapler, and scissors to quickly build a template that was a pretty good approximation of the correct shape. Next, I traced the inside shape of the ladder leg on a piece of cardboard and sketched in the outside shape. I made the legs wide enough to accommodate a 2¼-inch-deep tread on the main rungs and about the same on the folding section. This keeps the total depth of the ladder at about 41/2 inches and allows me to use 6-inch-diameter fenders on either side of the ladder to protect it from the dinghy.

Establishing the shape of the forward leg was straightforward, but the after leg was more complicated because it has to conform simultaneously to the geometric plane of the ladder and the receding curve of the hull.

The solid feel of a hull-hugging ladder gives boarders a firm leg up, above. It starts with a simple pattern, at right.

A perfectionist might dial this in with successive patterns approximating the desired result. Or you can do what I did and make your best guess to start with and shim it.

Tread spacing and freeboard marine surveys by Allport Marine Survey, Steilacoom, Washington, USA - Tony Allport, SAMSŽ AMSŽ

After test-fitting the cardboard patterns to the boat and making any needed adjustments, I had to consider the height and spacing of the steps. Several factors come into play here and they will be different for every boat. The treads should be evenly spaced to divide the boat’s freeboard into comfortable steps. The height of the lowest step above the water should be approximately that of the freeboard of the boat’s dinghy. The folding swim-step portion should be configured so the treads match up when it is folded up, and the bottom step should be at least 12 inches below the surface when it is folded down — as much as 20 inches is better.

When determining the width of the ladder, I took into consideration comfort of use and the limitations of the storage space available. The width of a likely spot in the cockpit locker determined a ladder width of 15 inches, which works well in practice.

I built the treads and the entire fold-down section out of 3/4-inch mahogany. I used solid lumber because plywood cannot provide the required stiffness to resist bending. I joined the two sections together with a pair of ladder hinges and attached a hook and eye to keep the folding section in place.

Making a classic ladder like this is not a difficult project. Once you have determined the overall dimensions and shape of the side pieces, the construction is very straightforward.