I doubt water intrusion will trip the breaker in itself. Other than a GFCI receptacle, almost all receptacles used, do not have exposed terminals and water is not a good conductor; the impurities in it could be the cause of short circuits. The GFCI receptacles can easily trip if current is bled off to ground. Water can conduct enough for GFCIs to trip out and before a circuit breaker in distribution panel or on the inverter would trip out.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7