Originally Posted by Jeremy
Having just gone mad and bought my first RIB I was more than a little shocked to hear that I might get roughly 1 mile (nautical or otherwse) per litre out of it! It has a 90 litre tank and I was thinking I might try Cherbourg (from the Solent) which I reckon to be 60 ish miles as the seagull flies for lunch one calm day! Am I going to need the RNLI and appear on the news or do I just go by myself with fuel tanks everywhere?
From some of the threads on the same subject it seems I need higher level maths and a ready mileage/ US gallons converter and a small computer. All I really need to know is whether I could make the trip at something less than full speed and the family on board!!
Is this your first boat? How much experience do you have? The question suggests you may not have undertaken any training (it was certainly covered in my PB2 course) ... in which case a cross channel trip is certainly ambitious.
[Edit - sorry Nos - already said this whilst my fingers were transferring thoughts to the screen.]
90 HP will use roughly 34 litres per hour at full throttle. So you have about 3 hours "endurance" at full power. You will probably get over 4hrs at optimum cruising speed. I think this is probably enough for a cross channel trip, but not a lot of scope for cock ups and almost certainly not enough for a round trip. If it was me I would take a spare 25-30L along in a portable tank and refil in france.
Normal recommendation seems to be to carry at least 20% spare in reserve.