Originally Posted by mccabe
I also have a Seamaster 30 foot which has twin perkins diesels and is a displacement hull ie pushes through the water up to her hull speed.I need advise on replacement props and have been told 16x14 "turbine" give better grip for reverse etc.Does anybody with experience know where I can source suitable props either used or new and can advise on other alternative sizes.
Would a visit to Beaulieu be useful? Many thanks in advance
Not many Seamasters on the Forum!
I reckon your best bet would be to get in touch with Steel Developments for both advice and supply.
However, the best replacements will most likely be pretty similar to what you have fitted at present. The size should be stamped on them somewhere.
With a shaft drive boat you normally go for the largest diameter that will fit - but allowing sufficient clearance between the blade tips and hull to keep vibration to a minimum.
You then match the pitch to the anticipated boat speed allowing for gearbox ratio and likely propeller slip.
The final variable is the shape and blade area ratio - basically how large the blades are. This is dictated by how much power the propeller is expected to absorb before it cavitates. This is the "Turbine" bit.
The Seamaster will probably only require small ish blades - but a larger blade area ratio may give better low speed thrust and reversing but may be marginally less efficient at your top speed.