Here is a picture of the GPS and RPM gauge on the twin while on plane when returning from a NJ Mainship Group raftup September of 2004. This was taken 2-3 miles off the NJ coast in the typical 3-4' seas. There was a slight north to south current so the pilot turned briefly to the West (watch out for that beach ahead!) to take the current out of the picture. (No pun intended.) Click picture to enlarge to read the GPS.

The GPS shows a speed over ground of 14 Knots (16.1 MPH) at 2800 RPM. There was about 2/3s of a tank of fuel. The main water tank was full. The larger port water tank was full and the starboard water tank was empty. The engines max rated RPM are 3300 but both actually turn at max RPM of about 3400-3450. Thus, 2800 RPM is about 82-84% of max RPM depending on which figure you use.

At this speed, the boat is on a slight incline but is not dragging it's bottom. There is a long flat rooster tail as seen in the pictures below.