Twin F250 needs new props?

[Tuna loco]

My boat is a 2008 Seaswirl 3301. All loaded up it is about 15000#. These are the props I have now, Series Saltwater Series II, Diameter/Pitch 15-1/4 x 19 Yamaha Part # 6D0-45970-00-00, 6D1-45970-00-00.
I am thinking with my heavy load and generally rough offshore conditions I should go to a 4 blade. I figure the factory props are for single engine lighter boats. I think my boat is at the upper end of weight and hull length.
Anyone have experience with a big heavy boat offshore 3 vs 4 blade props?

Harold

[rodbolt17]

not really any such thing as a factory or "stock" prop.
props are selected by the hull manufacturer in an oem hull or by the engine rigger at engine install.
the SS three blade series is a good design for offshore use.
a 4 blade may give slightly better stern lift.
whatever prop you end up with must be able to allow the engines to turn 5700-6000 rpm with THAT days load.