"Molded Hull Depth"?

[vic008]

Trying to sort prop size. Went to 'vicprop' and that is one of their questions (along with LWL etc)-what to measure for that please?

 

[TradewindSailor]

Moulded depth is the distance from the top of the keel to the underside of the weather deck at amidships .... essentially to the shear line.

 

[VicS]

It actually asks for "Molded hull draft (excluding keel)" ...draft not depth!

Does that not mean from the top of the keel, ie bottom of the hull, to the waterline?

 

[reeac]

It actually asks for "Molded hull draft (excluding keel)" ...draft not depth!

Does that not mean from the top of the keel, ie bottom of the hull, to the waterline?

That sounds much more likely as it's the immersed part of the hull which predominantly will determine power required and hence prop. size.

 

[Tranona]

Surprised they want that as it is not really relevant for a sailing boat auxiliary (assuming for your Sadler 29). The key data required is LWL (for theoretical hull speed), displacement for amount of thrust required, HP and revs of engine, shaft speed (therefore reduction ratio) and max diameter of prop. Try the Propcalc programme on www.castlemarine.co.uk If you are buying a new prop the supplier will recommend size.