Neat.
When I bought mine there was a length of scaffolding pole with a hitch on the end that came with it. Mod by previous owner due to beach launches on shallow beach. Two scaffold pipe clamps welded to the trailer chassis & adjusted by undoing & doing up the clamps.
Due to lack of after-dunking care although the outside of the trailer looked OK much of it was rotten as a pear & the middle section of two of the four bolts that held the hitch on had corroded completely away with the other two not far behind - so don't forget to look after your trailer!