Bertram33 User Forum

Left Mystic, CT Tues. enroute to Sailors Haven on Fire Island National Seashore, NY. 77.4 miles each way or 15.5 hours running time. burned 178 gallons of gasoline thru the 454's. Most of the running time thru Great South Bay, Shennecock and Moriches Bays was at 10-12 knts as the water depths are only in the high 5 foot range. Near the Moriches inlet shoaling was severe and near red markers 20 and 17 2.5 ft to 2.1 ft at about 25 % flooding tide. Just brushed the sand at 2.1 ft and at clutch speed, one engine in gear. The National Park Marina is perfect with 50 amp service and good water pressure. I got a chance to open her up near home with about a half tank of fuel and 30 gallons of water left. Clocked 25.4 knots at 4,050 rpm tops. I currently have 23 x 23 four bladed props.

Marker 17 should have read "18"

Great fuel burn, but then I realized you averaged 10 knots. I can't seem to get much more than 2 gallons per mile at 18-20 knots.

Scott, At a cruise of 17 > 18 kts @ 3100 rpm I get .6 .7 nmpg. I do have over size trim tabs & pick up almost a knot by dropping the bow down. I do have to pay attention to "bow steer" Al

Lobsta what does your boat top off at in RPMs? With my props( 23 x 23x 4 ) I seem to cruise at about 17.5 knts at 2900 rpms Don/ Mystic

I meant Don, not Scott. When my engines were built in 1978, Merc put a sticker on the valve covers that says WOT is 3800. Bertram owners manual says 4000. I had the bronze three blade props repitched down to 21X18 & the WOT is about 3900. Al

I have a wife and two year old too, so a "little" weight in gear I am sure. Normally the fuel is half full or better and water on the full side. Without the tabs we don't move much at all, but with enough trim tab I usually cruise 18-20k at 3100 rpms. My props are the original pitch (I forget off the top of my head 19x20 or 20x19?). The bottom was blasted and redone this spring. I keep a rough estimate of .5nmpg, I'm usually a little cautious with that guess, but it works well for us. The motors are 25+ years old, I would guess a few WOT's would be the end of them so I don't bother. When traveling I'm happier getting their slowly than getting half way their quickly.