Props/Performance/Altitude

[Sea Rider]

Impressive, assume at sea level use, in reality it's not a boat issue, could be well weight distributed, trimmed, engine sitting at the sweet transom height, it's a poor engine performance, has "soroche" a high altitude sickness. OTOH everybody except OP who already threw the towel is expecting excellent engine performance, definitely not with a 4 strokes 9,9 HP on a 14 footer and riding at altitude, no way...

Happy Boating.

 

[steelespike]

I agree it's not going to plane at higher altitudes but I think it should run faster than 6.7 mph.
And lower altitudes may actually plane. The 5.5" prop calculated at about 12 mph at 6000 rpm.
Now hopefully there is an elevation where it will approach 6000 rpm?