You're such Nay Sayers! All without having been aboard nor experienced or even seen a certain boat and engine perform! You can read plenty of different stats from manufacturers and owners and from that say as you like. However, I and my wife and some friends know what our little 14'8" Crestliner with 50 Johnson can and does do.
Visit http://retrocrestliner.com/1962%20crestliner%20catalog.pdf
THEN - - > Scroll down about 60% of the way.
Read about a boat extremely similar to ours, i.e. Crestliner's
Mustang "14" Deluxe. Text says: "...
reaches 20 mph in six seconds with three aboard and 25 hp range motor...
will top 30 mph with 40 hp motor [seemingly with 3 aboard].
Then - - > You [without any personal first hand knowledge of a boat's performance] tell me that with 50 hp and just me aboard our little Crestliner runabout that it will not do 39 mph... on a GPS readout at slack tide!!!!!
Please: Don't you have something better to do than to spend time contradicting what is GPS recorded fact???