Whether it is required by law or not, it's a good practice. If you hit a bump in the road, it's better that the trailer's suspension system absorb the shock instead of having the transom bounce and slam down on the trailer.
2015 Seaark 1872 MV CC Etec-90
Helix 12 CHIRP SI, HB 1199, MinnKota Riptide ST80/i-pilot Link, Bob's Hydraulic
Bitter Gun Owner