Fish Nautique thru hull mystery

Capt'n, I bet that fitting below the water line was for a live well. The bilge needs to exit well above the water line or it will back fill...I think.

Could I possibly have both bilge pumps hooked up to one thru hull or would this defeat the purpose of having two pumps because they would both pump the equivalant of one if sharing a bilge hose.

SemperFIsh wrote: Could I possibly have both bilge pumps hooked up to one thru hull or would this defeat the purpose of having two pumps because they would both pump the equivalant of one if sharing a bilge hose.

You got half of it...only so much water can pass through a given exit as it won't compress like air. The other is you'd need a way to keep 1 pump from pushing the water back to the other pump.

BuffaloBFN wrote: Capt'n, I bet that fitting below the water line was for a live well.

This makes sense since there is a piece of the old bilge hose sticking out a foot or so and chopped off at the front of the engine compartment that matches the remnant still clamped onto the thru hull beside the exhaust. I will reconnect this these two points with a pump and and new bilge hose to make the large fish box operational for bait once again. Back to the boat store.

Hi- I see you're in Tampa - I'm across the bay by Clearwater. I have a FishNautique I’m restoring also (Nothing major; replacing the tired engine with a FI 351, doing an Awlgrip paint job).

I have four large thru hulls out the back - the two top ones with internal flaps for deck drainage, the lower of course for the exhaust. Another small one that drains the little stern bait well, and yet another for the main live well/fish box. You might want to consider installing a petcock at this fitting (mine did not have one), as well as replacing the old hoses and ensuring they are double clamped - standard for all below waterline fittings.   One bilge pump thru hull on each side near the stern and above the waterline.

All bilge pump exits should be above the waterline (double clamped), and each pump needs their own. In typical two bilge pump systems on small boats like this, there is a primary pump and a secondary (or emergency) pump. The secondary one is usually the larger one (when it kicks on, something is wrong, and you need to get the water out). You don't share the same exit because you want full redundancy in the system - separate float switches, wiring, hoses, etc., so a broken wire or split hose won’t sink you.

SemperFIsh, I can take some pictures of what you're interested in - let me know. I am redoing mine, like I said, so it's not all there yet... Mine is the earlier model without the deep port and starboard bow storage, so I will be building that section up to match the later models and improve storage (and along with the storage, add some weight in the bow, as I believe you are also looking for). I will be adding an intake thru hull (1 1/2") at the stern for a 3700gph washdown and a livewell pump to be T'd to it after the shutoff valve. Anytime you put a hole in the hull at or below the waterline, you should glass in a pad inside the hull to bolt the flange of the valve to - if you Google this subject you will see lots of sites with instructions on this. One suggestion after reading your post may be to use a three way valve instead of the T if you are going to use one pump for double duty - that way you can use the full output of the pump for washdown instead of sharing it with the livewell.

I first have to glass that pad in like fishyflorida said. Sounds like we are doing the same thing. Would a piece of pressure treated plywood work or would a piece of starboard (marine lumber) be better? Not sure but I am thinking the latter for the simple reason its in the bottom of the bilge and is going to under water alot. Fishyflorida, do you have pics of your pump that's finished. Also, If I wanted to post pics on here and the pic is too big of a file, how do I shrink this down? Not too savy on the whole posting pics thing, Thanks

As stated, definitely don't use the treated wood; if you are following marine standards you will be using a bolt-down valve and will need to laminate a small (5-6") section to strengthen the hull at this location with a small piece of marine ply (with the hole drilled oversize in the wood first, so no open wood will be exposed near the valve). Starboard is excellent for many uses on boats, but not here – epoxy and fiberglass resin won’t bond to it.
Even if you just use a valve that threads to your thru hull, you will still want to add some lamination for strength, but you can forgo the wood. Clean the surface, grind with 60 grit, and add the roving and mat pieces soaked in epoxy resin. (mat first against the hull, then roving, then mat, then roving finally mat again. The mat helps fill the gaps in the coarse weave of the roving and makes it much stronger, as too much of just the resin is weak.

There is an excellent explanation of valves here: http://www.pbase.com/mainecruising/seacock_primer