How fast should I be going? I've got a 1993 20' Stingray 609 zpx with a Merc 4.3L LX Alpha One 180hp. Drive ratio is 1.84. Weight of the boat plus motor, fuel, gear, and myself is 2050 pounds (Boat and motor alone is 1575 pounds). At WOT I'm hitting 4800 rpms and GPS is tracking my speed at 45 mph. The prop is the factory 21 pitch prop. (Or so I assume.) The prop doesn't have any knicks or cuts in it, but a lot of the paint has flaked off, so the surface of the blades is pretty rough. The hull of the boat has two months worth of grime buildup from being kept in the water in a lagoon. Is 45 mph the speed I should be getting? The brochure for the boat from 1993 says with a light load I should be hitting 52 mph. I'm a first time boat owner, so I'm just wondering if a drop from 52 to 45 is typical for the load I'm putting in the boat, plus the slow build up of grime on the hull, or should I be getting a better speed? Thanks.
