Coosa Starboard vs marine ply

[Amberjack]

I keep a MarineWest roll up dingy under the cockpit on Amberjack. It has marine ply floorboards which make up about half the weight of the entire dingy so I’m thinking about replacing them with something lighter. Would Coosa or Starboard work for this application? It needs to be somewhat rigid although they are supported on the underside by the dingy bottom fabric. I’m OK with painting them but glassing them would defeat the purpose of reducing weight. 3/4” material.

[Tony Meola]

I think I would try Azak first. I think you would need to glass the edges of the cosa to keep it from tearing the fabric and starboard would be expensive compared to Azak.

[Yannis]

Doug, how big is your dinghy?

If its not too big, you will not save a lot of weight by swapping the floor.
If its small, like 2-2,5 m, it will be costlier to do what you propose than buy a new one.
The lightest dinghies are those with the inflatable floors, like the SUP’s.
Then come those with slats.
Then those with ply or aluminum floors.
Then the ribs.

[Carl]

Tony- Are there different grades of Azek? The stuff I am familiar with from Home Depot bends n sags unless supported.

[pschauss]

I used Azek for the floor panels and steps between my engine boxes. I braced them on the undersides with fiberglass angle iron to minimize flexing.

[Tony Meola]

Tony- Are there different grades of Azek? The stuff I am familiar with from Home Depot bends n sags unless supported.

Carl

No, it is only the thickness that creates the stiffness. But if it has some type of support under it might work. Heck, I see these kids using these big mats to float on. They are running and jumping on them, and this 1/2 inch of foam is supporting them. Water does strange things when things float on it. I am not sure what he has under the floor, but if it right on the bottom it will probably work.

[Amberjack]

Thanks guys, I'll take a look at Azek. The slats are on the bottom of the dingy which is flat and water supported so some flex is OK. They are for footing stability, not rigidity.

Yannis, I did a lot of looking and there are only a few inflatables that deflate and roll up to a dimension that will fit in my under cockpit locker. Its a trade off but I like being able to travel with a clean, open cockpit and nothing hanging off the stern. Every year I hear radio calls from boaters about a tender lost in rough weather in any of the various straits we traverse. But these full roll ups are cheaply built and this one has four 10" x 36" floor slats of 3/4" plywood. They are clumsy and heavy and I've grown to hate them. An inflatable kayak wouldn't work because we put an electric outboard on the tender and use it to travel a mile or two for supplies. So its pretty much what I'm stuck with, I'm just trying to improve it a bit.

[Yannis]

Doug,

All dinghies that I know are made in China and are using this pvc (I forget the name) material. So, really, unless you find a specific brand that uses hypalon (the original material of Cousteau’s Zodiacs) then they are all having a lifespan of around 3-5 years, depending on how much sun or hardship they go through before they start losing air from the seams. You may try and stick/mend them, but you're on their last leg so to speak.

Im on my third dinghy, they all cost me around €400-600 and they are all so similar, my current one is 2m30 with an inflatable floor and is spacious enough for 2 big guys, or two ppl plus a kid.
Because of high demand and covid, the prices were exorbitant here in Greece so I had one flown to me from “Orangemarine” from France. They have a very good service and very good delays.
Take a look at their website, some have inflatable floors. They may also have connections in your area, don't hesitate to write to them in the comments, they answer back !

Good luck.

PS: If I remember correctly hypalon made dinghies were made by Avon, Zodiac, Bombard and another one or two brands, but I don't know if they still make them as they are significantly more expensive than the pvc ones.

[Geebert]

Not one dinghy joke?