Simple answer is it sucked up some weeds and the transmission oil cooler is clogged. Easy fix, and something a person should do as preventive maintenance a couple times a season.
And yes, you can start a boat out of water and not see any immediate issues, but this will catch up with you with shortened impeller life and potentially an overheated boat on the water.
TANDEM AXLE TRAILER PACKAGE
4 14x5.5 Series 07 Black Accent Wheels
4 ST205/75R14 Kenda tires mounted & balanced
Delivered within the U.S. for $549
TRAILER WHEELS, TIRES & ACCESSORIES
Aluminum, Steel & Galvanized Wheels, Kenda K550 & Gladiator QR25-TS Trailer
Chrome and Colored Lug Nuts, Spare Tire & Wheel, Spare Tire Carriers
Aluminum & Steel Fenders - single and dual axle
Please PM or email me for a price quote. Email: firstname.lastname@example.org