Disclaimer: I'm a new owner and do NOT have my motor height/prop optimized yet.
I have 2003 2520xl 16degree MV with Yamaha F225 4 stroke on a bracket. Right now it has the Yamaha black stainless prop 15", 17 pitch.
Right now my WOT is 5400, with a speed of about 28kts. That is with 2 people on board, 100 gallons fuel, and about 600 to 800lbs gear.
We were able to cruise at about 4800 RPMs, and 24kts, and could have easily gone slower while maintaining plane.
Already have talked to Ken at PropGods and he recommended a Quicksilver Thunderbolt 15 3/4" prop, 15pitch, which will give me a little more hole shot, more top speed, and I'm assuming a lower RPMs at 24kts. To be determined, but I'm planning to set the motor height correctly once I find the right prop.
Personally I wouldn't want to fish 6 people offshore.......IMO that is too many.