stopping a leak

i have a 34 foot aluminum campboat thet i have had for 40 years.....the inboard and outdrive was pulled and junked many years ago...its just a fishing camp...it has a seacock that i left in it when i pulled the motor etc..then the back deck was rebuilt with no access except thru the hole left by the outdrive...this hole is above the waterline and i plan to pull the cover i put on it to get to the seacock which i suspect is leaking....i dont remember exactly how it was installed but i do remember a piece of wood with a regular galvanised faucet sticking up....my problem is this:i expect to find wet wood and wet aluminum when i get in there...i will be working thru the hole that the outdrive went thru....very little water pressure as that part of the boat is only inches below the water....what i need is suggestions....i have been looking and thinking of using a spray sealant....but i am not sure what sealant to use or if that would even work....any knowledge shared on this kind of problem would be greatly appreciated...thank you...Carl

one of the problems is i will not know what i have until i tear off the covering for the outdrive hole...altho this hole is above the water line i cant leave it open for any time to speak of....so i have to have what ever i will need on hand....thats the reason i was thinking the spray sealant...possibly with a good silicone caulk around the edge of the wood also...i think i can probably get to the hole under the boat with my arm to get a plug into it.....i dont expect it to be leaking thru that pipe though....i expect it to be leaking around the outside of that pipe...i dont really care what the end result looks like so long as the leak is stopped...sorry i cant give more info but i dont have it at this point..just looking for ideas...

something that will stick to wet wood is one need....they make an aluminum to aluminum sealer that can be used underwater.....i have used it before....messy but it works....the wet wood is going to be the big problem.....if the leak is around the outside of the pipe coming thru the hull then the water will be feeding between the hull and that wood..its going to be too tight in there to do any sanding etc.....the deck is 1 1/4 inches thick and i sure dont want to cut it out if i can avoid it...and i repeat...i dont care how it looks after i get thru...if i got a mound of caulk and sealer under there i dont care....i am going to reseal the outdrive hole if it stops the leak and forget it...i have had this boat for 39 years and am 73 years old and just want a dry boat...the floor in the boat is raised so the boat is basicly dry....but i have everything that you could want in there including computer....in fact i am the only one that even knows it has a leak...

i have a auto bilge pump installed at the low point ......works great.....the low point is not in the rear.....its at the front on the port side....the counter and stove and a 5 cubic foot freezer is on that side in the front cabin..on the other side is the small fridge and a good size air conditioner and a couch...the rear has the bunks and behind that the shower on one side and the commode and sewer treatment plant on the other...hot water tank under a bunk....misc boxes of stuff under both bunks...it appears level when you step down into it but i have loaded it on purpose to make that the low point...my thinking at this point is to work some silicone caulk into where the piece of wood that holds the pipe meets the metal as best i can...then spray the foam all over the whole thing.....the leak is not that bad for a boat that size and age....the bilge pump comes on for about 5-7 minutes about once a week...and then only if you add a persons weight to the front left of the boat....and the leak will go away for months at a time...i can pump it out and then suck it dry with a shop vac and it may get water in it in 2 days or it may stay dry for a long time..acts like a loose rivet and it may very well turn out to be something like that instead of the sea cock...

i am pretty sure the leak is at the aft end of the boat for this reason.....if i cripple the bilge pump where it wont work the water level will only get so high in the low part of the boat....i think as that front left of the boat goes a hair deeper into the water the rear is lifting a tad and the pressure is equalizing and the leak is either stopping or becoming more of a weep.....this is just a theory i have after many frustrating hours thinking and such...the construction of the hull is thisicture an industrial john boat...the inside ribs are about 6 inches in diameter and either 3 or four inches high and go across the bottom and then taper off and go up the sides a bit...the ribs are 6 inches apart...lotta ribs...then the floor is on top of these ribs with indoor/outdoor carpet on top of that...the only place that is open is a small cut that i made for the bilge pump....so its impossible to see where the leak is without removing the floor...

do you have a brand name for the foam you mentioned?thanks

thanks again....i had thought of extra weight in the front of the boat....3 coolers full of water is the plan....there will be no standing water there so no shop vac needed altho i have one down there.....the hair dryer i had not thought of....good idea(the leak is draining forward)....i have used the foam before but i thought you may know a certain brand....now all i got to do is line up my son to help me and borrow wifes hair dryer....easier said than done on the dryer....will let you know how the job comes out...dont know when that will be though...thanks again...

this is the campboat we are talking about..