New prop, less wake
- Thread starter DAKA
- Start date
Whitelighter
Well-Known Member
Most wake is from the displacement of the hull, not the wash of the prop
Searush
Well-Known Member
Don't worry about DAKA, his boat never makes any wash anyway & it has it's own personal exclusion zone for (& from) all other vessels.
DAKA
Well-Known Member
Well spotted searush, you know your mobos well, its a Princess, they hardly make any wash at all, just ask Haydn for confirmation
I've been pulled up for speeding once or twenty times but never for making excessive wash
Jim@sea
Well-Known Member
I suppose because its got a greater wetted area facing the way you are pushing against then a greater thrust is being achieved, thus more speed for less revs.
Tranona
Well-Known Member
Just stumbled across this while eating Fish & Chips out of a news paper !
it would be nice if Hamble and Chichester can increase their speed limits to 10knts , the same as Portsmouth, Poole and Langston
Note they are being highly selective in the magazine testimonials they quote. The YM one they got in the test because the design was different - and it was not compared with a conventional 3 blade. Anybody who has read that article will know that there was widely variable performance from the different types of folding and feathering props, but no conclusions. A back to back test in PBO on a real boat showed slightly inferior performance than the regular prop, so, not surprisingly is not included in their site.
The product is very expensive - over twice the price of a conventional 3 blader, but less than a feathering prop which offers clear advantages over a fixed prop on a sailing boat (although not necessarily in motoring).
As ever, the market will decide.
ricky_s
Well-Known Member
Just stumbled across this while eating Fish & Chips out of a news paper !
it would be nice if Hamble and Chichester can increase their speed limits to 10knts , the same as Portsmouth, Poole and Langston
The harbour has a new manager now so going to write to her to review.
It seems the nagging about little sailboats sailing across the main channels stopped then doing so, so it is well worth having a go to get things changed.
DAKA
Well-Known Member
Well done on getting the dinghies sorted
Good luck with the speed limit, it does make good sense to increase it , 8knots is ridiculously slow for such a large expanse of tidal water.
With modern computer developed hulls and props making less wash there is no reason why 10knts shouldnt be the limit in 90% of the harbour.
Perhaps trot fairways should be kept at 6/8 depending on the width but you hardly see anyone on their trot boats anyway.
ricky_s
Well-Known Member
Well done on getting the dinghies sorted
Not sure if it was just down to me but I did hassle them about it a lot!
oceanfroggie
Well-Known Member
Just stumbled across this while eating Fish & Chips out of a news paper !
it would be nice if Hamble and Chichester can increase their speed limits to 10knts , the same as Portsmouth, Poole and Langston
10kts is a disaster speed for wake generation near moored vessels and for fuel economy. 35-45 foot hulls just dig stupid holes in the water at 10kt in harbour and mooring areas. 6-7kt speed guarantees displacement speeds and acceptable wake.
pappaecho
Well-Known Member
It always amazes me the wake created by a 40 foot boat doing 8 knots in Portsmouth harbour, and the same lack of wake from the 40,000 tonne ferries which ply to and fro from Portsmouth
Solitaire
Well-Known Member
I'm with you on this. Plus, it's not a limit in most cases it is a maximum - there is a difference. The overriding factor is the effects of wash. Yachts for example can travel faster than power boats without creating wash due to the hull design. I have often been overtaken by sailing boats going up the Hamble or in Portsmouth because at thier speed I would be rocking all and sundry off their Chablis!
In my days as a harbour patrol officer in Portsmouth we were always telling mobos to slow down due to excessive wash - very often got 10 fingers, but had to "explain" that wash was the be all and all!