4 blade prop on a 20?

[McGillicuddy]

What Bushwacker said, minus the Mirage. I can't speak to the Rebel Blades. I don't think the Merc Mirage is appropriate or even available in that size.

In a 4 blade, try a Merc Alpha 4 or the Solas version, Amita 4 - I think, if you're fine with aluminum. These props are very similar to the time tested merc black max.

If you want stainless, check PowerTech's SCD 4 which is a 4 blade version of Yamahas semi cleaver (also a very good design for your combo), or the MQF4 which is a 4 blade version of Mercurys Black Max geometry. Size will be roughly 13.5 x 15p or 13.25 x 17p. Great stern-lift and handling and lower plane speed from all. Hole-shot will also be very good. 3 blade variants in each of those props are also available. Each of those should get you 34-37 mph. Maybe more with the 3 blade stainless options.

The 4stroke is about 400 lbs & the 2 stroke closer to 350. What prop are you running now on what model motor. I think the merc black max is just perfect for a 115 on a 20 SeaCraft, but the MQF or SCD stainless props can't help but improve performance. Splitting hairs? Maybe. About $200 difference for SS 3 blades. More for 4 blades If you have a 4 stroke I would expect better lift from the Merc design or the MQF from PowerTech props.