Recent content by lohring

We actually went over 100 during one pass, but Mike had to lift a little. Below are the data logs from our record runs. The battery current and voltage is from one 6S pack. There were 6 packs in series and 7 in parallel. In my opinion, records must be sanctioned by a recognized body and set...

Sorry, you're right. The results are below. Lohring Miller

My only personal experience with offshore racing was in the 2010 Cowes Torquay Cowes race. It was very rough. Mike, Dry Martini's owner, broke ribs, and it took us almost 6 hours to go the 200+ miles for an average speed of 36 mph. Only 13 out of 26 starters finished. Mike was in the 2011...

I would like to congratulate my friend, Mike Bontoft for his fourth place overall, second place in class B finish. Mike has run his 35' 1973 Cigarette, Dry Martini, in the historic division in the past. The picture is from the 2010 race. Lohring Miller

There's been some progress in this area since the thread was started. A realistic looking electric outboard package has been developed. It can go 45 knots (51 mph). Note that duration isn't mentioned. However, take a careful look at the power plant price in the brochure at the bottom of the...

The two day US Safety at Sea course is much more comprehensive than the British version. Because of potential political issues, I took the British course as well. The US course involves among other things, real, timed immersion suit drills in the cold Pacific ocean, fire fighting real and...

Very nice scale boat, but I'd be surprised if it would go 60 mph. Our modified 26 cc engines develop around 6.5 hp at 16,000 rpm and typically drive offshore style 46" deep vee monos around 60 mph with surface drive props. At this scale, even small waves are very significant. The flat bottom...

I was not there. I'm too old for the really rough stuff. Congratulations to my good friend Mike Bontoft for his second historic class win and sixth place finish. This year he didn't suffer broken ribs like 2010 or a broken nose like 2011 when he crewed on the third place boat Pippa. There's...

We ran several versions of Mike's design to set model boat records. Wings in ground effect are an excellent way to reduce water drag. Unfortunately, the rougher it gets the poorer they work. I'm afraid hydro style boats will never be able to run in offshore conditions. Cats are the only...

Our original design for a lead acid powered boat was an inboard. Here we felt we needed to fly a heavy boat so the design below was modeled in 1/4 scale for testing. When lithium polymer batteries were allowed, we realized we had a power plant that would fit in an existing 80+ mph design that...

I worked with Enerland for our boat's batteries. The batteries still cost $14,000. Since they have been bought by A123, You would need to start all over. Battery charging is also an issue. We used standard model boat chargers that could charge two batteries each. That took 21 chargers at...

Yes, but it only runs for 10 minutes. You could do that on 5 gallons of gasoline. Lohring Miller

I need some real data from a real offshore boat. Specifically, weight power, and speed. Let's go with two 150 KW (200 hp) motor/speed control systems. At 450 volts each would draw 337 amps. The input current with 97% speed control and 95% motor efficiency would be 366 amps each or 732 amps...

Let's design a boat. Help me pick a fast, small hull, probably an inboard cat, and tell me how much power it takes to drive it at a particular speed. Please try to eliminate hype. I can calculate a rough power plant design to go say 15 miles at that speed. Lohring Miller

Steal away. Using 300 shaft hp requires 375 hp or around 280 kilowatts of input power. With a 500 volt power supply you would need 560 amps to the motor. Two thousand pounds of lithium polymer batteries would be around 6330 cells. (By the way, 2000 pounds of gasoline is a little over 300...