Yacht Slide Size: How to Measure Rail-to-Waterline

The captain is leaning over the upper-deck rail with a weighted line, the deckhand is calling out marks from the swim platform, and the owner’s kids are watching from the sun pad as if this were the most important number on board. For a slide, it is. Getting the yacht slide size right comes down to one measurement, the rail-to-waterline drop, taken the right way, on the right day, from the right spot.

In short: measure straight down from the top of the rail where the slide will hang to the surface of the water, with the yacht loaded the way it is on a normal charter or family day, not empty at the dock. Then match that number to a maker’s published range: FunAir sizes from 1.5 m to over 10 m of drop, and Yachtbeach lists each model by railing height. When you sit between ranges, ask the maker before you order.

Why rail-to-waterline decides the yacht slide size

An inflatable yacht slide hangs from a rail or deck edge and runs down into the sea. If it’s too short for the drop, the slide hangs steeply and the ride gets abrupt; if it’s too long, extra slide lies in the water or doesn’t sit properly on the rail. That’s why makers don’t sell yacht slides by yacht length. FunAir puts it plainly: the right size “depends on your rail-to-waterline drop and your yacht’s deck layout.” The Yachtbeach dealer Ritz Marine lists its Magic Yachtslide 4.6 for railings 270 to 350 cm above the water and tells buyers to choose by that height.

How to measure, step by step

1. Pick the launch point. Decide which deck the slide will start from and which section of rail it will hang over. Measure there, not at the highest or lowest point of the deck.
2. Load the boat the way you use it. Fuel, water, tender and toys aboard, and guests if you can. A retailer’s guide for boat slides says to measure “loaded, with the people and gear you normally carry, not empty at the dock,” because a loaded hull sits lower.
3. Measure from the top of the rail straight down to the water surface. A weighted tape or line dropped over the side works; on calm water, two people make it easy (one at the rail, one reading the mark at the waterline).
4. Write it down in both metres and feet. Makers in Europe quote centimetres; US dealers often quote feet.
5. Note the deck layout around the launch point: how much flat deck there is behind the rail, where the anchor points are, and anything in the way of the slide’s path, such as a swim platform, a tender garage door or exhaust outlets.

FunAir also publishes a Slide Measuring Guide and will size a slide from your General Arrangement (GA) drawings, the deck plans that come with the yacht. If you have the GA, send it along with your measured drop; the maker can then build a 3D fit model before it makes anything.

FunAir sizes by drop

FunAir publishes its slides in bands of rail-to-waterline drop, with a guide to the yacht lengths each band usually suits. The FunSize and Hanger Mini are QuickShip models held in stock; the bigger ones are built to order. All are sold by quote.

FunAir model	Drop (rail to waterline)	Yacht size the maker lists	Setup the maker states
FunSize	1.5 m (about 5 ft)	Up to 20 m (66 ft)	1 to 2 crew, under 15 minutes
Hanger Mini	2 to 3.5 m (6.6 to 11.5 ft)	Up to 30 m (98 ft)	1 to 2 crew, under 15 minutes
Hanger	4 to 6.5 m (13 to 21 ft)	30 to 50 m (98 to 164 ft)	About 20 minutes
Hanger Extreme	7 to 9.5 m (23 to 31 ft)	Over 50 m (164 ft)	RapidFlate blower
Riser (custom)	Over 9.5 m (31 ft)	Over 60 m (197 ft)	About 60 minutes
Self-Lifting (custom)	Over 10 m (33 ft)	Over 60 m (197 ft)	Not published

Notice the gap between the Hanger Mini (up to 3.5 m) and the Hanger (from 4 m). If your drop measures around 3.7 m, that is exactly the case to send to the maker rather than guess. FunAir also makes bow, stern and curved slides from 3 to 12 m, and a fully custom flume slide, all built to order.

Yachtbeach sizes by railing height

Yachtbeach names its drop-stitch Magic Yachtslides by size and lists each for a railing-height band. Dealer figures:

Yachtbeach model	Railing height	Weight (dealer)	Handling
Magic Yachtslide 4.6	270 to 350 cm (8.9 to 11.5 ft)	46 kg with bag	Electric pump, 10 to 15 minutes
Magic Yachtslide 5.2	380 to 460 cm (12.5 to 15.1 ft)	About 99 kg	Not published
Magic Yachtslide 6.2	460 to 540 cm (15.1 to 17.7 ft)	About 116 kg	2 crew
Magic Yachtslide 7.2	540 to 620 cm (17.7 to 20.3 ft)	About 120 kg	2 crew

Again, there’s a small gap: 350 to 380 cm isn’t covered by any band. A railing at 360 cm (about 11.8 ft) is a question for the dealer. The 4.6 attaches to a swim platform, a railing or a Yachtbeach platform, and it packs to 96 x 61 x 35 cm in its bag, which is worth knowing when you plan stowage.

Other makers

FreeStyle Slides custom-makes its sealed-air FreeStyle Cruiser to fit each yacht, and press reports quote the maker as generally recommending leg support for slides longer than 5 m. Superyacht Tenders & Toys builds slides to order with a flat or 45-degree entry and lifting bridles for a crane or davit. Both size from your measurements; neither publishes a size chart we could use here. See all of them on our makers page.

Common measuring mistakes

• Measuring at the dock with empty tanks. The boat sits higher than it will on a full day out.
• Measuring from the deck instead of the rail. Slides hang over the rail; FunAir’s slides sit 10 to 15 cm (4 to 6 in) above the rails so they don’t press on them, so the rail height is the reference.
• Measuring the wrong deck. If you might use the slide from two decks, measure both and say so when you ask for a quote.
• Forgetting the anchor points. FunAir notes that “proper anchor points and rigging are essential.” Measure where they are relative to the launch point.

Get a size checked

Yacht slides are sold by quote, and FunAir quotes about 35 days for custom work while QuickShip models “can be shipped within days.” We don’t sell slides, but if you send us your drop, deck and yacht details through Request more information, we’ll pass on what the makers publish and help you ask the right questions. For the full comparison, see the best yacht slides, and for rigging, installing a yacht slide.

Measuring questions

What size yacht slide do I need for a 30 m yacht?

It depends on the drop, not the length. FunAir lists the Hanger Mini (2 to 3.5 m) for yachts up to 30 m and the Hanger (4 to 6.5 m) from 30 m, so a 30 m yacht could fall in either. Measure first.

Does the tide change my measurement?

No. The yacht floats, so the distance from rail to water stays the same as the tide rises and falls. Load is what changes it.

Will a slide damage my handrails?

FunAir says its slides sit 10 to 15 cm above the rails, “ensuring there is no direct contact, stress, or pressure on them,” with the slide held by anchor points and rigging planned at the design stage.

What if I measure between two sizes?

Send the exact number and your deck layout to the maker or dealer. Both FunAir and Yachtbeach have small gaps between bands, and custom sizes exist for that reason.

Back to Fit & Sizing, or read on: will a slide fit my boat? and water depth and clearance.