Sold old boat but he has not transferred it

Sold my old boat in November. Thought he'd do the transfer but he still hasn't. Sold through Facebook marketplace. I've closed my Facebook account since for various reasons so don't have his name just texts. Have pictures where he went fishing with his wife and kid. I've sent text asking if it's his number still. No response.
What am I in for. If I got his information another way its lost in the house.

He will be trying to find you when the tags run out. Lol .I think there is a place on the TPWD page to let them know that you sold the boat.

There is a place for that but it requires his information. I don't have that.

X2

The information that TPWD needs should be your information if I remember correctly. Once you do that then the boat cannot be re-registered until past fees are paid.