My surveyor says my tanks are excessively large! What would be the appropriate capacity for a 30footer planned for weekend and occasional 4-5 day trips for 3-4 adults? Wash basin and galley.
Really depends what you use the water for, and whether you have electric or manual pumps.
We carry 140 litres, have a pressurised pumping system, and can easily get through that in a day if all (2 adults & 2 children) have a shower, washing up after three meals, plus other cooking needs.
Manual pumps greatly reduce water consumption though!
we have pressurised water, but surely if you require a sink full of water for washing up it won't make any difference wheather it is manual or pressurised!?
With respect to your surveyor but that surely is a comment rather than advice to change them? The Liz 30 tanks I had were sausage flexibles under each main cabin bunk taking pretty well all the space under each, although a spare Danforth anchor did sit under one, protected by a bit of carpet from chafing the tank. One tank fed the galley via an in-line Whale electric pump (not a pressure pump) with a simple switch, the other fed the loo washbasin. Having the two tanks separated was useful as there was a spare when the first ran out, I can't remember if we washed more than we drank or vice versa though. Having plenty of capacity is a bonus IMO, it certainly was when we had our Liz and access to water as we were on a swinging mooring and anchored when away (fewer marinas anyway then) was less easy. You don't have to have them full if it bothers you or Mr Pernickety.
Harlequin has 2 x 100gallon tanks, one on either side (~440 litres) on a 37' boat. It lasts for ages though (unless SWMBO has a shower /forums/images/graemlins/grin.gif)