Estimating Fuel Costs for Boston Whaler

[Kierran]

The non-profit organization that I work for may be receiving a donation of a Boston Whaler (don't know exact size; most likely 17-ft or under). I am not sure the size of the engine either (sorry). I will hopefully know more next week. But in the mean time, I have been asked to come up with a draft budget of the costs associated with operating a boat (I know they're numerous and high).

One of the costs is obviously fuel. Can any Whaler owners around that size class give me an idea? I appreciate any info and will update this thread when I find out more specifics. This boat would be very useful to our organization, but the powers at be don't want to take on anything we can't handle, etc.

Thanks in advance.