Cruising Range 2008 Mariner 330 5.7 Crusader Gas

[MBoone]

Hello. New to carver and would like some estimates /guess on the cruising range of the 2008 Mariner 36. Crusader. Gas 5.7 330 hp river and lakes at 80 % 4,000 rpm. 16 knots’.. loop prospects for us.

Ideas to increase speed range of this boat?

Thanks,
MJB

[km1125]

You'd probably be at 18-20 GPH per engine, so at that speed probably 0.4-0.5 MPG. If that has the 250 Gal tank, that might mean around 90 miles cruise (at 80% of tank).

Note too that the distance travelled would be significantly affected by the river currents, either increasing or decreasing the amount by quite a bit. IIRC, if you're going WITH the current, you'd probably want to travel as slow as you can (hull speed if possible), to get multiples of the MPG. Going against the current it's more of a time thing, where you'd want to at least be on plane.

[bud37]

Source of the post Ideas to increase speed range of this boat?

Welcome to the forum.......run the boat at around 7 knots ( around 6-7 GPH total ), it will take considerably longer but will extend the range total.....remember to employ the 1/3 rule for safety to cover the unknowns.......1/3 out, 1/3 back and 1/3 in reserve if heading to open water.

[bud37]

Actually a great addition to any cruising boat would be a fuel flow monitoring system that interacts with the GPSmap. Takes away much of the guess work, allows efficient running no matter the conditions you are confronted with and is a good troubleshooting tool as well.

Good luck with your travels.....

[Cooler]

Kinda surprised you're only getting 16 kts at 4000 RPM. Those engines are thirsty at that RPM range. Traveling at hull speed, 7 or 8 mph will increase your range significantly, but take much more time. Make sure your bottom is clean as possible and a total tune up on engines. Hopefully you will be going in a southerly direction down the Mississippi, same as current. Also verify fueling stops. Some locations closed over Covid, and the high water levels, and never opened up again. Good luck! er

[tomschauer]

As cooler mentioned, you should be WELL above 16 knots at 4000 rpms. something is up. That boat should be about 28 - 30 mph at 4000 rpm if all is well and bottom is clean.