Fuel Tanks - Advantages & Disadvantages of under floor vs above deck

rbw156 · 31 May 2005, 12:52

I can see advantages and disadvantages of under floor vs above deck fuel tanks. In particular, I can see the condition of the above deck, however, it is exposed to the elements and takes up valuable deck space. Whereas the underfloor is a neat solution, but it is heavier.

What do you think? In particular, do you have any horror stories of under floor tanks leaking?

nugent · 31 May 2005, 16:38

must admit i have been worrying over, getting water in mine, or if it leaks.. what do you do then,

interested to see what the experianced hands have to say

Hightower · 31 May 2005, 17:34

you can get a good range of tanks from Tempo products (do a search) these are normaly the plastic type and make tanks for under deck as well as above.

I have one of these in my BWM and it's as old as the RIB (10 years). It's a console type tank that sits mainly in the hull but comes though the deck a bit into the console.

swginn · 31 May 2005, 19:00

I think it depends on what you want it for. If you're planning long range cruising then under-deck tanks will give you more range and more storage. However if you just plan on going out for day trips an above deck tank is easier to maintain and change if anything goes wrong but will drastically reduce your range.

Whats more important IMHO is the tank material and its location. It should be located so as to balance the boat as best as possible (under-deck tanks make this a lot easier). Also I would say to go for an aluminium tank ahead of stainless as the stainless tanks do tend to split, whereas the ally ones have a bit more flex in them.

Petrov · 31 May 2005, 19:36

If you have the fueltanks under deck you will get low center of gravity which is an advantage for how the boat behave in water.

marios · 31 May 2005, 20:26

well some times above deck tanks are smeltly and cause discomfort to the passengers you have ....

Hightower · 01 June 2005, 08:45

Quote:

Originally Posted by swginn

Whats more important IMHO is the tank material and its location. It should be located so as to balance the boat as best as possible (under-deck tanks make this a lot easier). Also I would say to go for an aluminium tank ahead of stainless as the stainless tanks do tend to split, whereas the ally ones have a bit more flex in them.

What's wrong with plastic?

swginn · 01 June 2005, 10:51

Quote:

Originally Posted by Hightower

What's wrong with plastic?

Nothing at all!! I just forgot about them, as a lot of people do when considering larger size fuel tanks. Ally and plastic ahead of stainless any day!!

Just been looking at the Tempo range, do they do anything larger than 190 litres capacity?? Where I am there isn't any petrol available at the waterside and so the next RIB will have to have as large capacity as possible. I would consider plastic as an alternative to a powder coated ally tank if I could get at least a 300l+ tank.

Hightower · 01 June 2005, 11:13

Would you consider a 2 tank set up? Either a self leveling option or the seperate selection way. Would be more flexible in the setting up in a smallish Rib.

swginn · 01 June 2005, 11:49

It's something I might consider, alright. Although it's definitely only speculation at the moment. Just something I've been thinking about when we do decide to change ours in a few yrs time. Who knows what will be available then I suppose. For the moment we're happy with the XS, but you'll always be thinking of bigger and better things

rbw156 · 01 June 2005, 11:53

My thinking at the moment is that for an outboard of more than 100hp, then an under deck tank is probably the most practical due to the required size. For < 100hp, then two plastic above deck tanks is probably OK for day trips. Also, there is the expense of an under deck tank at about £800 (fitted).

Is it possible to fit a plastic tank inside a single jockey seat?

Rupert Bear · 01 June 2005, 15:11

Yep, I have the Tempo 70l plastic mounted in my single seat jockey. Great place to have it out the road. Breather on back of console high up and a small round waterproof hatch above the filler cap to access hose connections and cap for filling.
Roll up to the petrol station, open hatch and unscrew cap and fill, no hassle