Lamoore tri-hull dinghy test

Buster supervising the trials...

Lamoore yachts at Palm Beach make some stable easily driven dinghies and I’ve been keen to try one out with a Cruise 4 and a 1003 and today I got my chance…

The 8 foot dinghy is probably a bit short to get optimum speed but it is one of the most popular sizes and with the tri-hull design is a really stable small dinghy.  Optima batteries weigh in at 80kg and we found that they sat well just in front of the middle seat and with the pilot on the back seat the balance was about right.

Aaron planing with the Cruise 4 at 8 to 9 knots

It felt really fast and fun and the hull cut through the bow waves of other boats without slamming. Top speed was 9.3 knots and mostly we saw between eight and nine knots.

At full speed the power demand was about 3500 watts so the speed was limited by the maximum revs of the motor.  This means we can expect to get more speed from the higher pitched prop.  Due to a technical anomaly I no longer have the speed prop 🙂 But will be getting another one soon and will do some more tests then.

Transom is fairly high and prop so close to fresh that it sometimes ventilates

We also tried the 1003 on this dinghy and really, this is the motor that best matches this dinghy size—its 80 kg lighter than the C4 and its four Optimas and so there’s much more payload capacity. And more room in the dinghy as well without four batteries in front of the middle seat.

Close-up of 1003 - the best match for this boat's use as a tender

Lamoore have a good range of dinghies and we’d really like to try their 9ft 6″ version of the tri-hull which is reported to get really good planing speed with only a 6 HP petrol outboard.  One will be available soon, and I hope that I can also have the speed prop to test with this dinghy.  I think the Lamoore dinghies are a good match for the Torqeedoes and we plan to do more trials to suss the right combination.

The results are plotted on the chart below. The curve has a dramatic change of shape when the boat starts planing. I’m also not sure why the curves don’t fit so well as is usual.  I’ve used a “power” trendline as in other charts but it seems to be lower at the ends than I would have expected.  You can easily see the raw data points plotted there as well.  The blue line is the Cruise 4 running in displacement mode, and the orange data point is the power/speed point when the boat is planing – its clearly out of sync with the displacement curve.  The resistance must drop off dramatically once it gets on the plane.  Also plotted is the green line which is the data for a 1003 on this dinghy.  This is the mostly likely combination boat and motor to be used when used as a tender for a yacht.

Lamoore have a Torqeedo 1003 on display at their office at 1017 Barrenjoey Rd. Palm Beach and you can call them on 02 9974 5222. If you drop in be sure to check out their great tri-hull dinghies while you’re there.

The curves could be dodgy - look at the data points...

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