I stuck a 9 gallon plastic tank in that very spot 33 years ago to replace a tank I didn't have. It was a week before heading out on weeks vacation with boat. So its what was available that would fit. At 9 gallons it light on water...figured I could replace easy enough down the road.
9 gallon tank, pump sits on top. It is enough water to wash hands, do some dishes n glasses for a few days. Then its time to fill.
After 33 years, I think I'll keep it. Maybe next week I'll get around to mounting it as its just sitting there.
Jeremy it depends on how important domestic water is for you. As Carl has demonstrated if you use the boat primarily for fishing a 9 gallon drop in tank will be adequate. If you do some research you should be able to find a roto-molded poly tank that would fit well inside the old shell and give you closer to 20 gallons. Take the entire old tank out and you could probably fit a 30 gallon molded tank. Or just slap a fiberglass top on it and get 30-ish gallons. These figures are guesses. Whatever you do I suggest installing an access port on the top so you can clean it in the spring. They accumulate sludge over the course of the year.
Interestingly your old water tank is the tank I plumbed in for my holding tank. We get about 3 days at anchor or the dock before having to pump out if we’re careful. My water tank is located under the companionway. I took out the old leaking aluminum tank and installed a roto-molded tank that gives me about 3 days domestic use. Nice symmetry. We always carry a couple 2.5 gallon off the shelf jugs for back up as water isn’t always available at the dock in BC in dry weather once you get away from the populated areas. At the end of the season the 2.5 gallon jugs go into the basement for earthquake/emergency supply.
Thanks for posting this, I’m reminded not to step on the top of my holding tank!
I had Speedy Tanks build a H2O tank to fit on top of my main fuel tank. It is about 3.5" high and fits well under the center floor. It holds about 13.5 gallons of fresh water. This year, I'm planning on adding a separate fresh water Aux tank behind the fridge to hold another 5 gallons or so of water.
The longest we've stayed on the hook was 6 days That's pushing 13 gallons of water capacity limit.
Rick Ott
Fly N Fish
1969 B31 Flybridge
Hull # Don't have a clue
Thanks for the suggestions - would definitely need to update the fill and would be nice to also have a clean out option - I might just put a topper on it. The Gelcoat interior is still in decent shape maybe I'll also update the discharge fitting that's screwed into the bottom. My holding tank is under my companionway
If you fabricate a top be careful of clearance. There isn’t much room between the old top and the floorboards, if you add a 1/2” new top measure your fill fittings carefully and locate them between structural elements. I wound up doing a lot of sawing and chiseling.
Good point Amberjack - I have some left over coosa board that should make a nice topper - I plan on redoing the interior anyway - so a little modification to accommodate the tank would be easy.
I did some trimming of the flanges yesterday - Ordered a fill fitting too
I would remove the old tank and install a rubber bladder tank of the size that would fit my needs. No aeration valve necessary. Easy to clean. Lightweight. Cheap. Practical.
Need I say more?
I believe the old tank is 18 gallons. Years ago RONCO who is the big player for tanks, made a custom tank for me at that time was a reasonable price. It appears they no longer do custom tanks.
I have been considering the Ronco B103 20 gallon tank, myself. It appears to have an equivalent 25* "dead rise" and might work but the dead rise is a little steeper towards the mid section of the boat than the transom. I'll have to measure the hull at that section and/or the old tank.
The simplest, most practical, easiest to clean, fastest to install, cheapest, easiest to tell how much water is left, solution to water tanks.
What's NOT to like about them. Thirteen years and counting...
t is getting brutal. I was talking to the bait shop owner the other day. He told me he did not sell as much offshore gear this year because everyone focused on the Blue Fin inshore and ignored the Yellowfin and Big Eye in the canyons.
Much easier and cheaper to run 10 miles than 90 miles.
Yes, Tony, plus a third one under the galley sole.
All interconnected with garden hose and garden plastic fittings.
With vanes, so you can use them separately if you prefer.
Not one connection has ever leaked in 13 years.
No need for aeration valve, as they collapse as water depletes, like in wine boxes with a tap.
To clean, disconnect, fill with 10-20 liters of water, walk on them barefoot to agitate dirt and empty, repeat if need be.
Don't think twice...best water tank solution since the invention of bread.
PS: If you feel the surface underneath is rough, just place a sleeping bag foam mat underneath. This is to also cover any screw heads or nuts lying underneath.
