Not quite sure what you asking but if its the black bit I could see that it would allow the trail or to be kept more leven when attached to a tow hook that is quite high. Maybe it was a long boat and the stern was too close to the ground when on tow hook?
Thing is its a the same height it would be if I drop the top 'T' bar underneath and do away with the bracket, only a 6mtr destroyer,
Guess its staying unless I get bored,
Just find it strange and curious of its purpose
MY BIGGEST WORRY IS THAT MY WIFE(WHEN I"M DEAD)WILL SELL MY TOY'S FOR WHAT I SAID I PAID FOR THEM.