Cruising in a power boat

[edmundsteele]

We also made the switch from sail to power cat last year. In the past 11 months we have made two 400 mile passages plus another half dozen “overnighters”. The power cat is a Leopard 47PC weighing in at around 16 tons (I say “around” because she can carry 1 1/4 tons of water if you fill all of the tanks). This vessel was “driven” on its hull from Cape Town to Tortola and spent the next five years orbiting the BVI’s as a Mooring’s charter. The engines are twin turbo-charged 150HP Cummins. She has the standard two fuel tanks, 150 gallons each. (Yes, the props are counter-rotating, the direction of rotation determined by the transmissions). Our fuel consumption observations are as follows.

Idle speed on two engines @ 1,000 RPM produces 6 knots. No idea what the fuel consumption at “idle” is.

Two engines at ~ half throttle – 1,800 RPM gives 8.5 to 9 knots depending upon sea conditions or 200 miles per day. She burns 1.5 gallons per hour per engine at this speed. Range without reserve 850 – 900 miles.

One engine at half throttle – 1,800 RPM hangs in at 7 knots and she is burning 1.5 gallons per hour. Range without reserve 1,400 miles.

Ed