It is not so much the mass of the boat, but the windage of the hull. High freeboard, cabin, 20 knots breeze, and you are going to need something like 6hp high thrust prop. Low freeboard, low cabin, 10 knots breeze, and a Honda 2.3 would do it.

I've got a 5hp on my Soling, one of the guys at the club has a 3.5 on his. To be honest, mine is probably a little overkill, though it'll punch into 30kts of wind and still keep it moving. Otherwise, it'll get it to hull speed with at least another 25% throttle to spare. Hull weight is 1035 apparently. Add on the rig and a bunch of garbage and I'd probably be somewhat near the 1600kg range.

The main reason I picked it was that the smallest engine you could get with a proper reverse gear was 4hp, but the 5 is exactly the same engine with different tuning (so same weight and everything). Other advantage is that you can hook up an external fuel tank as well as the internal, which is a nice little feature.

In Qld if you have over 4 hp as a motor you have to have the boat registered and a boat license. Not 100% sure but that was the reason why I kept my outboard to a 4 hp. Not sure about the laws in other states.It also has a reverse gear and as mentioned in an earlier post above... this is the lowest hp motor that has a reverse gear which is really handy if your coming in too hot on a mooring or pier. Which all of us here have experienced I'm sure. I also kept it as a 2 stroke for lightness on the transom of the Dart. I would have bought a much lighter motor like a 2 to 3.2 hp if I could if they had a reverse gear.This out weighed the weight (excuse the pun) The lighter the better on the transom. If you can get in behind and re-enforce the transom it may be well to do so. Otherwise you will over time notice gel coat cracks on the transom which may lead to other things.

Yeh, no hp restriction in NSW - it's based on speed (10 knots off the top of my head).

I also looked into the Torqueedo electric. Weight is amazing, from what I've heard, equivalent to 3.5 hp power, but price is a doozy - $3000 ish. For that price, you could buy three normal outboards.

Suzuki claim lightest 4 strokes 23 kgs for 6 hp. Offering discount at Sanctuary Cove Boat Show.
Dont forget no more twos coming in from 30/6

Hi all,
Thanks to all who helped me make my decision.
I bought a new 4hp Tohatsu with forward, neutral and reverse weighing 20 kg.
I went out on the harbour motoring with six on board for Vivid. Happy with it.
Raced on Sunday and it seems fine in 15 to 20 knots.
Over that, I used the head sail (20-25kts) to get back to the berth.
It may be more difficult motoring to a mooring in that sort of wind.

Planeray said..
Yeh, no hp restriction in NSW - it's based on speed (10 knots off the top of my head).

I also looked into the Torqueedo electric. Weight is amazing, from what I've heard, equivalent to 3.5 hp power, but price is a doozy - $3000 ish. For that price, you could buy three normal outboards.

Actually incorrect, any boat with an engine exceeding 4 kilowatts (5 hp) requires registration in NSW.

LooseChange said..

UncleBob said..

Planeray said..
Yeh, no hp restriction in NSW - it's based on speed (10 knots off the top of my head).

I also looked into the Torqueedo electric. Weight is amazing, from what I've heard, equivalent to 3.5 hp power, but price is a doozy - $3000 ish. For that price, you could buy three normal outboards.

Actually incorrect, any boat with an engine exceeding 4 kilowatts (5 hp) requires registration in NSW.

UncleBob is correct, the 10 knot thing is for licensing purposes ...

"The speed at which a boat is driven determines whether you need a licence. Anyone who is the operator of a power-driven vessel operating recreationally on NSW waters, at a speed of 10 knots (approximately 18.5km/h) or more must have a general boat driving licence"

"The following vessels must be registered with Roads and Maritime when occupying NSW navigable waters:Power-driven vessels that are powered by an engine with a power rating of 4.0 kilowatts or more (greater than 5 horsepower)"

Yeh, no dramas - I was only referring to the licence component originally - didn't even think about registration.