I just got back from a week long vacation at Lake Almanor in Northern
California. I definitely paid attention to my boat travels and
cruising speed due to the price of gas.

I used almost 3 full tanks of gas (18 gal/tank) in 9 days of running my
17' runabout with a 130 HP 4 cylinder AQ130C Volvo engine. Not sure
how many engine hours we notched during this time, but at/near WOT, it
burns about 3.5 gallons per hour. I started off with a full tank from
a street gas pump and then paid USD$3.50/gal for 91 octane one day and
USD$3.00 for 87 octane the second time I had to fill up on the water.
All told, I figure I spent almost $150 in gas on my vacation. As I
recall, we figured out it cost us about USD$10/engine hour.

Bob