Canister Life Raft mounted on Hardtop

[Off the Hook]

Does anyone have any advice on doing/not doing this???

I would like to mount a life raft in a canister on the hardtop of my boat. I have seen a number of Gradys on the website with this done, but of course when i called Grady they said don't mount it there :bang :bang (they always say don't add anything to the hardtop)

I was thinking of have a rectangular backing plate made to mount on the underside with through bolts...

Any opinions or suggestions???

Thanks

 

[ocnslr]

The usual considerations are:

1. Adding weight up high changes the dynamic stability of the vessel. On a smaller boat this might be an issue, but less likely on a 330.

2. Strength of the hard top, with the 80-90# of the canistered raft applying various loadings when underway. I can't really comment on this, except to say that GW will, of course, be conservative and say "don't do it".

3. Actual deployment in an emergency. If your 330 took on water to the point it swamped, it would most likely capsize. It has flotation, but it won't keep it upright (lots of photos of Gradys turned turtle). This now puts your liferaft about 8-10 ft underwater and, if it should autodeploy, it will simply be stuck there.

I consider #3 to be the biggest factor in NOT placing that piece of survival equipment "up on the roof".

Ours is in a valise.

Brian

 

[fishbust]

My 6 man raft weighs between 70 and 75 pounds. Add the canister and it does not seem like an unreasonable amount of weight to add.

I think maybe Grady does not want to be blamed for hardtop coring rot if you do not properly seal any holes you make in it. Can't blame them.
Or maybe slamming in the ocean can cause it to crack the hardtop.
Either way, they must have a good reason for saying not to do it.

My raft I keep in midship berth in valise. When I go offshore I take it out of there and tie it up in the bow.
A raft cooking in a canister in the sun doe not appeal to me.

 

[everwhom]

Realize this is an old thread, but I've been researching this topic in depth as I'm purchasing a new-to-me 330 Express, and am planning to get a life raft. (I'm upgrading from a slightly smaller boat and have about 10 years on the water with many offshore fishing trips)

I think the 3rd point that Ocnsir made is extremely important and often overlooked by most small craft boaters when selecting a life raft or Category I EPIRB (auto-deploying). As Ocnsir points out, our boats have basic flotation so they will not sink even if completely full of water. They will, however, likely capsize. The hydrostatic mechanism for both life rafts and Cat I EPIRBS is designed to release at a depth between 1.5 - 4 meters, or 5-13 feet. So a life raft on the hard top *might* release if the boat is capsized, but it might not. If the canister is mounted on the bow, the chances of it deploying are probably less, as capsized boats tend to float bow-high. The point is that the the mechanism *must* activate when it's below 13 feet to meet SOLAS and USCG standards.

Check out the pictures of capsized boats in this article on Boattest: http://www.boattest.com/view-news/3228_ ... -angry-sea
And here's a detailed description of a typical hydrostatic release mechanism: http://www.cmhammar.com/products/onboar ... las-model/

Cat I EPIRBS have the same release requirements (and presumably very similar mechanisms), but on most small boats (i.e. under 50 ft) that I've seen these mounted on, they are in the cockpit and even less likely to release if capsized, as they will be closer to the surface than the hard top. The bottom line is that automatically deploying life rafts and EPIRBs are meant to be released when the boat is actually sinking, so if your boat has basic floatation and is small enough that the mounting location of the device will not definitely be under 13 feet of water, it may not deploy if you merely fill with water and capsize.

So my conclusion for my 330 Express that it's worth mounting a Cat I EPIRB to the hard top (or tower in my case since I am probably going to add a 1/2 tower), but only as a secondary, *backup* device. I will continue to carry a Cat II, manual deploy EPIRB, in my ditch bag. I'm going to get a valise life raft (probably the Revere Coastal Commander) and keep that and my ditch bag handy. Not exactly sure of the best location to stow these as I don't have the boat yet, but I might try to strap the life raft to the underside of the hard top with some quick-release tie downs. Seems to me that if you need your life raft, you probably need it in a hurry, so having right above your head isn't a bad spot. I'm not at all worried about the added weight as the 330's hard top is super beefy.

Sorry for the long-winded post, but thought I'd share what I learned.

Joe

 

[Fishtales]

Hi,
I'm sure you could do this without a problem with the right support structure under it. There is a genuine concern as the hardtop skin isn't that thick and the coring is balsa.
I would think plates topside and under along with plastic spacer tubes all sealed with 4200 would ensure you have no problems.

 

[everwhom]

Bit more on this. I'm realizing that I had a fundamental misconception about automatically deploying life rafts. They are actually STILL meant to be manually deployed. The automatic deployment is essentially a backup feature in case the boat sinks (and of course only useful if your boat actually does sink!)

Here's a useful video from Revere on selecting, stowing, and deploying a raft. (skip to about 4:30) https://www.youtube.com/watch?v=Nhinv4cBm4c

So the stowage location choice comes down to the right compromise of having it out of the way, protected from the elements (possibly in a canister), but accessible enough to be able to chuck the whole thing into the water and pull the painter line so it inflates. The hard top of my 330 Express is definitely not the right spot for me as far as that's concerned.

 

[Fishtales]

I looked at this and ended up going with a valise. It is in a robust bag so it can be moved around if needed. I keep it in the mid berth which I use more for storage (rods on ceiling, tackle bags, clothes and other day trip items). If we sleep, I just pull it out and store on the bow out of the way to maximize room. Personally I think the valise is the way to go.