The Art Of Swim Platform Design: Extending Accessibility

2021 Sea Ray SLX 400 swim platform design. Photo: Sea Ray via MarineMax.

Above: 2021 Sea Ray SLX 400 swim platform design. Photo: Sea Ray via MarineMax.

Boats have grown new appendages, with deck extensions and aft platforms now coming in lots of different shapes, designs and sizes. Swim step, swim platform, hydraulic platform, terrace, beach club – whatever you call it – boats are now packed with features that get you closer to the waterline, expand available deck space, do away with acrobatics when stepping aboard from the dock, and make water ingress and egress easy for young, old, and even the four-legged.

The days of unsightly, hard-to-use boarding ladders are gone. Not just a conventional surface attached to the transom, the swim platform of today has to serve multiple purposes, be easy to use and look like it’s a flowing extension of the boat itself when deployed. Let’s look how the swim platform, in all its many forms, has proliferated all segments of boating.

Hydraulic Swim Platforms

The submersible, hydraulic swim platform has been an admired feature of power yachts for decades. A couple of jointed stainless steel arms are bolted onto the transom and capped with fiberglass and/or teak. The hydraulic pump and cylinder(s) that lift and submerge this platform are generally housed inside the machinery space of the vessel as are the control boxes, cabling and electric activation switch(es). For example, the Monte Carlo 6 has a hydraulic platform with integrated brackets to carry the tender. Just submerge the platform, load the dinghy and then raise the whole thing and off you go.

Another version of a hydraulic platform can be found on bigger powercats. The Leopard 50 has a platform between the transoms in lieu of davits. Not only can this carry the tender or a PWC, it’s also a great staging area when going diving or swimming, giving people a place to sit to put on their fins and gear. More importantly, it makes boarding the boat from the water easy for the mobility challenged. Just swim up, have a seat on the partially submerged platform and get raised up. No upper body strength required to enjoy a good swim.

The drawbacks of these platforms are that they’re heavy, especially if capped with teak. The transom may have to be reinforced to carry the platform and the structure itself has an upper limit on weight capacity so the size of tender matters. These platforms also extend the overall length in the slip which can raise the rent in the marina, and since they’re moving parts that often sit in salt or even freshwater, malfunction issues are common.

The hydraulic platform has found its way onto smaller vessels in past decades. Express cruisers like the Beneteau Gran Tourismo 40 have an option for a submersible platform that also doubles as a place for the chef to stand when grilling at the outdoor galley module integrated into the transom.

Platforms With Outboards

Inboard boats have enjoyed swim platforms (hydraulic or fixed) for a long time while outboard boats have had little more than a well ahead of the transom where the motors attached. That has changed significantly as outboard engines have grown in popularity. For example, the Regal 26 OBX Super Sport Crossover is an open bow family day boat powered by a single outboard. Fixed fiberglass swim steps protrude on either side of the motor providing a place to sit and put on a waterski or climb up via the integrated swim ladder.

Outboard engines can be a particular challenge for anglers. Lines stretching aft get tangled in the motors but not if you can fish right from the aft-most portion of the deck. Take for example, the Solace 345 and its patent-pending FishThru transom. The cockpit extends back, essentially forming a swim step of sorts between the two outboards. Bring the fish aboard via the transom door or check your dive gear just before taking the plunge. Having multiple outboards hanging off the transom is no longer an excuse not to have a swim platform.

Origami Hull Sides And The “Beach Club”

People don’t want to swim and play behind outboard engines and propellers which is how opening hull sides have come in vogue. The award-winning Sea Ray SLX 400 has taken water access to a whole new level. The model comes in a choice of inboard power – which allows for a submersible hydraulic platform, or triple Mercury Verado outboards with swim steps on either side. Either way, two great deck extensions exist. First, there’s the full beam passage just behind the multifunction sun bed. Second, the aft starboard hull section hinges down to create extra deck space from where you can jump off and play in the water and away from the engines. The Azimut Verve 40 with triple outboards is another example where the portside aft hull section drops down when the boat is stationary.

A more extreme version of this origami effect is the EVO 43 which has recently morphed into the EVO R4. This swanky day boat or superyacht tender opens up in ways that have made many call it the Reformer Boat. At anchor, both hull sides slide out and open, adding several feet to the aft beam. Then, the middle section of the swim platform lifts up and out forming a dive platform with steps leading up to it. If you continue to press the button, it will swing aft and down with the platform submerging and the steps switching to down mode. The whole process from boat to private island takes only 30 seconds and it’s a head turner.

Large power and sailing cats have gotten into the drop-down hull side game too. The Lagoon 78MY is a sizeable cat that will most likely be crewed. The master suite is in the forward starboard hull and it’s a posh affair. If the owners opt for a private swim in the morning, a hull door opens to form a secluded swim platform. The guests can lounge on the aft platform while the owners indulge in their own little watery world.

As boats have become capsules of luxury, the beach club idea has taken root. The point is to recreate (night or day) at the water level to enjoy sports, water toys or glasses of bubbly. Originating on superyachts, the idea was to open up the transom to reveal a lounge or bar at the waterline. On some boats, this has become a significant space but the new Prestige X70 has a more compact take on an old concept. Here, a section of the transom opens up into a settee complete with cushions and pillows. When done, just fold up the rumble-seat and get under way.

One company that specializes in all sorts of swim platform layouts is Nauta Design. On superyachts, Nauta Design has even patented some of their work which often includes multiple hull side openings, pools integrated into to the swim platform and mini-platforms extending off the main platform. Via their innovative design, the company has turned the aft part of the ship into a virtual resort.

Drop Down Transoms, Extended Swim Steps (And Other Funky Designs)

Transom extensions and steps aren’t just in the realm of superyachts. Many modern sailboats have added a drop-down transom to extend the aft cockpit and create a teak beach. On larger models like the Bavaria C57, the transom drops down electrically revealing a dinghy garage. On smaller models like the Beneteau 30.1, the transom can be lowered and raised manually with a line since it’s cantilevered and doesn’t require a lot of effort or strength.

Sailing cats have always sported small swim steps at each transom but these have grown like on the HH55 uber-cat where you can tie up the dinghy and kayak on one side and then go swim off the other side unencumbered.

For a unique approach on small craft, check out Cobalt’s award-winning E-Step available on their R series non-outboard models. This is a small boat answer to a powered platform with a step that lowers into the water at the push of a button. Use it to step up after a swim or sit on it and cool off.

Another Cobalt innovation is the Splash & Stow and this just barely fits the definition of a platform but it’s so cool, everyone who sees it, wants it. This extended, inflatable platform is the perfect water toy that attaches to the transom to provide a lounge or play space. Even Fido will love to slip around on this. The Splash & Stow won an award for the way it deploys and then neatly packs away with little fuss.

The Back End Is The Right End

Boats are designed with multiple social spaces be it an aft or forward cockpit, a flybridge or one of the unique platforms and swim steps described above. The idea is to extend the living space and provide easy access to the water because you’re on a boat and that’s what it’s all about.

Written by: Zuzana Prochazka

Zuzana Prochazka is a writer and photographer who freelances for a dozen boating magazines and websites. A USCG 100 Ton Master, Zuzana has cruised, chartered and skippered flotillas in many parts of the world and serves as a presenter on charter destinations and topics. She is the Chair of the New Product Awards committee, judging innovative boats and gear at NMMA and NMEA shows, and currently serves as immediate past president of Boating Writers International. She contributes to and, and also blogs regularly on her boat review site,