Hi Chuck,

Just a few notes about my latest project. My first project, Bubbles which was featured in Duckworks in 2004, proved both too small, due to the family growing taller, and too slow, as said family found fishing in particular and power boating in general more in line with their nautical tastes.

I ‘tested the water’ so to speak with a secondhand 13’ planing dinghy that proved a bit too secondhand - the transom broke, and investigation showed serious rot. Not only was it not worth fixing, it sort of confirmed my view that building new was safer than buying an old boat unless you’re 100% certain of the build quality, the history and the design..

My family found fishing in particular and power boating in general more in line with their nautical tastes.

A search of my boat building library led me to settle on Bolger’s 15’ Diablo (in Dynamite Payson’s Build the New Instant Boats). It met all my criteria of being big enough for 4, small enough to be cheap, and fast enough with my existing 15hp Yamaha outboard. I also made a clear choice for a ‘workboat’ finish – there were no concessions to a fine finish, nor were expensive woods used. As a result, the total cost was only about NZ$700 (approx US$500) for the hull. Bottom line – this is a boat to be used and enjoyed, not cosseted in a garage, and if I damage it then repair or replacement isn’t going to break the bank.

I also made another key economic decision – almost everything was done with hand tools. Not only did this save money, but I found it faster, as I discovered I could cut the panel curves more accurately with a cheap handsaw than with any power saw, hence there was no trimming nor associated waste material/time.

I didn’t take any construction shots, but I have included some pictures from the sea trials. I can report it exceeds my expectations. As well as being drier and faster than the smaller boat, when I went offshore a mile or so into some wind chop, the flat bottom pounded a wee bit but no worse than the old V-bottom dinghy. I also got a friend in a larger boat to pace me using his speedo – just under 22 knots solo, and 20 knots with a passenger, back in calm conditions of course. The Diablo also didn’t seem to have any noticeable transition from displacement to planing speeds with 3 aboard – the faster I went, the higher it rose in the water. No fuss, no hassle.

I didn’t take any construction shots, but I have included some pictures from the sea trials.

All is not perfect – I found that on very tight turns my short shaft engine cavitates like crazy, but is fine in normal use. And solo I need a tiller extension as the trim is too tail heavy with just me, even though I am a light 78kg (170 lbs). Both problems would be fixed by using a long shaft motor and remote controls so I can sit on the forward thwart, which does of course mean a bigger motor. If I can do 22 knots with a 15 hp, I wonder how she would fly with a 25hp….

Only one thing left to do now – think of a name!

Cheers
Maurice O’Brien
Auckland
New Zealand

Read: "The Birth of Bubbles" by Maruice O'Brien