Bulkheads do not add floatation?

In another thread here I talked about drainage and how I’d like to install a stern bulkhead in my son’s kayak ( the LL Bean version doesn’t come with one). I contacted Perception to ask about getting the plans for the bulkhead.

Here is my question:

" I bought an LLBean Manatee (Perception Prodigy) for my son and would like to install a bulkhead for safety. Could I get a copy of the plans/layout and or dimensions for the Prodigy stern bulkhead? I already have the cc foam and 5200 sealant. Thanks,K"

The reply:

“Unfortunately I wouldn’t be able to send that out to you as I don’t have that available to me and it is proprietary. A bulkhead however is not a safety measure…it is simply to keep storage areas dry. They do not add floatation to the boat. If you were to take the bulkhead out and completely submerge the boat, it will still float due to the nature of the hull material. New bulkheads however can be purchased through www.harmonygear.com.

Thanks C”

I completely understand that they wouldn’t want to give me the plans, but please " A bulkhead however is not a safety measure… They do not add floatation to the boat."

Seriously? a large volume of trapped air doesn’t aid in floatation?..ANYTHING that helps a water craft float makes for a safer boat…

I guess that must’ve been some kind of CYA legal statement, that’s the only way I can figure anyone would say that.

His statement makes no sense, but
you should be aware that installation of a watertight bulkhead is difficult. It isn’t so much the drawings and the dimensions as it is the factory method for getting the thing glued in properly.

I bought a touring kayak with no front bulkhead, and rather than take a chance with a shade tree bulkhead addition that might leak when I least wanted it to, I installed a large float bag. If I want to carry drybag storage in the bow, I tie the drybags in under the float bag and then inflate the float bag full. That’s added flotation I can trust.

of course it adds flotation
A sealed, air-filled compartment will obviously add floatation. Now, sometimes the seal on hatches on that type of kayak are not entirely water tight, but the compartment will likely not flood suddenly.

For that matter the closed cell foam itself will displace water and add flotation.

If you just want to add flotation and don’t care too much about storage you could just put a float bag in the stern.

Installing a bulkhead in a finished boat is tricky but if you want to do it I would apply a strip of 1" masking tape around the outside of your hull exactly where you want the bulkhead to go on the inside and make sure you get it nice and square. Get some fairly stiff wire and use the tape as a guide to bend the wire around the outside contour of your boat.

The wire will approximate the outside contour of your boat and will obviously be bigger in area than the interior. You can either trace the wire outline onto a piece of stiff cardboard, cut out a template and use that for final shaping, or you can just trace the wire outline onto your foam and shape that.

bulkhead shape
Run a tape line around the boat where you want the bulkheaqd. Take a bunch of playing cards (or cardboard cut to that size) and tape them together on edge going around the boat. Two people make this go easy. You obviously will do it in two pieces - deck and hull. It makes a pretty accurate tracing of the hull shape. You may want to put a small hatch opening somewhere in case you get water in there after installing the bulkhead.

You need to send an e-mail or
letter to the General manager letting them know that someone is passing out wrong information

Jack L

It won’t help
Ever since Perception and Dagger were acquired by WaterMark their customer service has ceased to be a source of reliable information, in my experience.

The situation didn’t improve when Confluence acquired WaterMark, and I doubt it will be improved by J. H. Whitney acquiring Confluence.

My take…
A watertight bulkhead adds flotation. But making a bulkhead truly watertight can be challenging, especially in plastic boats where the hull flexes over time from being strapped down etc. Not enough to sink you, but enough to be annual maintenance. It isn’t a bad idea to pick up float bags or dry bags to stick in there as a backup.

The company is correct, the boat will float without a forward bulkhead. It will potentially float pointing straight down, which leaves the paddler hanging around waiting for a motor boat to come along and help tow the thing. Or swim to shore and hope they don’t encounter a motor boat on the way.

The lawyers have taken over many otherwise decent companies when it comes to safety or liability concerns. The results are alternatively overly protective or downright dumb.

In a way…
a watertight bulkhead does add flotation, but in another, the company is correct that it does not provide reliable flotation. In a larger sense, there is nothing that actually does, so I guess they’re correct in a way on that, too.

Bulkheads can, and often do, leak. As was said, in plastic boats, they will eventually fail, so they should be reinforced with float bags or storage bags (if gear is carried) in the compartment as well.


I disagree on your take on a plastic…
boat bulkhead.

We have twenty year old plastic sea kayaks and I have never had to reseal the bulkheads.

We have five year old high end carbon/kevlar QCC’s, and I have already had to reseal them.

It is what is used as a sealant and what material the bulkhead is made from.

A high density foam bulkhead will give with the flex of the hull

Jack L

She’s talking about boat owner installed
bulkheads in plastic boats, so there may not be ground for disagreement. I know Necky and other companies have long, successful, experience putting bulkheads in plastic boats.

My take is actual experience

– Last Updated: May-31-14 12:59 PM EST –

First sea kayaks were plastic - CD Squall and Necky Elaho (DS). After a year of use I was getting a couple of cups of water into one of the bulkheads in the Squall, I forget which. By the time I sold her I found resealing twice a year was a better idea. The Elaho was also getting a little water in towards the end of the first season, but I was not responsible for that maintenance so I don't recall if it progressed. Won't sink the boat, but suggest that plastic boats will not always stay dry.

By the way, the bulkheads in those plastic boats were exactly what you describe, dense foam sealed around the edges, and both were dry for the first season.

Among the fiberglass boats - two NDK, two Valley and one P&H Vela, all sea kayaks - just one of the NDK boats has a small leak that might be the bulkhead. Not sure - it has been at the least elusive to figure out. The rest of the bulkheads in the glass boats are dry despite mostly years of use and abuse including rocks and an occasional drop off the roof of a car. But then we tend to be attracted to those crappily made Brit boats...

The OPer might have your experience. Or ours. What we found is not unique among other with whom we have paddled.

Interesting. I will have to keep an eye
on my Necky, which probably is of the same vintage as your Elaho.

It occurs to me that, to the extent that hatches are not only watertight but approach air tightness, expansion and contraction of air within the bulkheads, due to temperature changes or to mechanical force on the hull, is going to want to breach the bulkhead seal.

That wouldn’t be a problem for the contents of the rear bulkhead of my Looksha Sport, because my weight is such that I don’t carry more than the “ten essentials” and a light lunch. Maybe I’ll find one of my c-1 or k-1 whitewater float bags and just loosely inflate it in the rear compartment as insurance.

While the response is odd
A bulkheaded stern compartment won’t make it “safe”.

legalese hairsplitting
…but I agree with the float bag recommendation.

Yes & No.
Under normal circumstances, yes a “sealed” compartment of closed cell foam & trapped air will add floatation to your kayak. However do not rely on a bulkhead with a rubber cover for safety floatation. My Wilderness Systems Pungo has that same system (factory installed, with no leaks in the bulkhead seal). Last summer while kayaking I decided to take a swim. While trying to climb back in, I flipped the kayak, filling it mostly with water. Having a pfd on, I wasn’t too concerned, especially since I had a sealed bulkhead, right? Well as I climbed on top of the stern end (bulkheaded end, which was floating high in the water, while the bow sunk), the pressure caused the hatch cover to blow off & she started sinking. Lake was only 10’ deep, so I wasn’t totally SoL, but let’s say it wasn’t a fun day from that point on. Wife & kids were in their boats & helped me bail mine out, but I bought float bags for all our kayaks after that.

So in my experience, no, a bulkhead won’t keep you afloat in the time when you need it most. Float bags are far superior. Just be careful of sharp objects around them.

For the record- I was climbing on the stern in an effort to get the cockpit out of the water so we could bail it out. Looking back it would obviously have been smarter/safer to just tow the half sunken boat & me back to shallower water to work on it, but it seemed easy enough to carry out my initial rescue plan. Hindsight…

after about 10 years, most of the bulkheads on the plastic boats I used leaked to some degree. They were bone dry through the early years and, over time, had a cup, then a liter, and eventually became fairly useless.

This has a lot to do with storage, admittedly, but plastic hulls (particularly on longer boats) tend to deform over time.

I can’t comment on boats made in the last 5-7 years, though I have no reason to believe that these are any more reliable (though they may be).