The three VCP hatch covers on my new 'yak bulged up slightly on the ride home in fairly hot weather yesterday. I know some folks do - and others don’t - drill a small pressure relief hole slightly above center in the bulkheads to alleviate this concern. I’d like to do that and wonder if there is any significant downside?
Counting on P.Net to come through again,
Glenn
Tsunami Chuck Said
Tsunami Chuck said he heard stories of Brit boat hatches building so much pressure due to altitude changes that they blow bulkheads. He just takes the hatches off for transport. That is what I am doing.
No downside at all
I’ve put 1/32" holes in the bulkheads of every commercial boat I’ve owned and a few others as well, and it has never created any problems. My experience has been that boats stay drier than when the bulkheads aren’t vented. You never have to worry about pressure differentials or hassle with taking the covers off. If you ever decide you want to seal the bulkheads again, all it takes is a dab of glue or sealant.
Venting
I drilled holes (1/32 inch) in the bulkheads of my aquanaut and I have had absolutely no problem. I practice rolling and I practice doing re-enter and rolls and I have never had a drop of water in the compartments. When I first got the kayak the hatches bulged in the heat (transporting on the roof of the truck) and sucked in when I started paddling in the colder water. It was enough to cause me some concern. Since I drilled the holes there is no problem, the hatches stay in place and the compartments stay dry. I would recommend this method without qualm.
Eeek!
I was wondering about the altitude question on Sunday after driving home from a paddle using my wood boat. I’ve always noticed that on my plastic kayak the neoprene covers (under plastic lids) get sucked in after rolling practice.
After doing 20 rolls in the wood kayak, I opened the hatches to check for leakage. The weatherstripping seals and knob closure seem to work very well, as there were literally only a couple drops of water in each hatch compartment. OK, so far so good.
But when I got home, which entails more than a 2000 foot elevation gain, the hatches hissed audibly when I opened them again. This always happens with my biking water bottles when I go up in elevation. With the plastic bottles, it’s merely amusing. With my wood boat, it has me worried. Now I will go out to the shed and check the (wood) bulkheads to make sure nothing got damaged. Thanks for the post. I guess I will need to drive the boat home or anywhere with substantial elevation change with the hatches open (not a thrilling prospect what with dust, rain, and UV exposure to unvarnished epoxy in there).
Ditto
Drilled the holes in the bulkheads, never had any problem
This seems like an obvious question…
… but I’m assuming that, with a day hatch behind the cockpit, I’d drill all three bulkheads?
“Well, duh!” is a perfectly acceptable response 
Glenn
Maybe right
Brian may have the best and most confident information and experience on this subject.
I was told to either leave the covers off when traveling or leave them cracked open a bit.
I find my Valley covers are very secure and breath when slightly cracked open. However, my wife’s NDK covers seem to seal even when ajar.
If 1/32" holes are good…
then are 1" holes 32 times better?
please advise - I’m standing here with the cordless drill at the ready
Even better…
why not removing the bulkheads?
Ventilation would be perfect
No, BobDobbs
By my calculation a 1" hole is over 1300 times better than a 1/32" hole!
Jim
Drill the holes…
Dit-to
It’s actually recommended by the good sir Nigel himself in the NDK ‘manual.’ Drilled all mine and absolutely no downside. Went through the burping stage with my daughter years ago, and didn’t feel the need to repeat. Drill away.
32^2
Uh, by my calculation it’s 1,024 times as good, but perhaps there’s a “fudge factor”* in there I’m neglecting. 
- rob
*“Fudge Factor” - Homer Simpson’s favorite “reality show”?
I Wonder
I wonder if the previous owner might have already drilled holes into the Skerrey? Maybe better check …
my take…
drilling is probably best, but I like seeing the hatch covers dome up…lets me know the hatches are water tight.
Scared of that!
Being as retentive as I am, I just had to do the math. I came to the same conclusion: 1024. I thought I was the only one, so I was just afraid to admit that I did it!
Removing the covers
keeps them out of the sun. Another good reason
to put em in the car (if its not raining).
could be a good use for
ye olde 303!
DONE! Thanks all!