I have had the boat out about 8 times in the last month and
have watched my fuel usage.

1995 271, 502 efi, b3

400 litres= about 105 gallons for 8 full 6-7 hour days.
I think that is freakin good...
Works about to $50-55 cdn per day @ $1.00 per litre in Canada, about $4 U.S per gallon
What can 4 people do for that kind of $$$.
Not much
Can't play golf.
Can't have steak and beers.
Could barely go to a movie.
Couldn't go to a theme park.
Half of one person could go the a good concert.

Gotta like it

something is wrong in your calculation if I understand correctly... 50-55$ AN HOUR could be ok, althoug maybe a little less if polite on throttle, but 50-55$ per day ?????

only if you idle to go at the beach and come back at the end of the day...

a 502 at WOT would burn roughly like a 496, 30-35 gal per hour. I know you are not running wot, but let's say running at 3000 - 3500 rpm, my guess is you would burn...15 to 20 gal per hour, x 3.78 for liters = 56 to 72 liter for an hour, at 1$ per liter is between 50 to 72 $ an hour...

If it is what you say it is, and you can guarantee it, I buy your engine and send you one of mine!

Seriously, that's what I used. I think it was 417 litres exactly x .378 equals 157. us gallons,
might be 7 days not 8 though, still good
Typical day, 11 am to 6-7 pm, mix of wot,
cruise on plane, idling around,
obviously not racing around all day,
but that's how I use my boat.
I think I'll keep this engine.

on a yearly basis, taking my total liter of gas bought last year, divided by the number of hours on my hour meter, that includes starting engine time, docking, cruising some higher speed but no really WOT, my twin 454 - 485 hp uses 72 liters per hour.

indeed, yes , keep your engine! it is a really good one!

yep, that's lots of fuel.
keep in mind,
I am only 27 ft , single engine, about 5700 lbs.
Bravo 3 as well, which probably helps.
Also, I am in a large harbour, bays and ocean and conditions determine how hard you can run a 27 footer.