The Liberty sounds right; I think she was one of the first ones built. 110' Vosper Thornycraft design built in Louisiana, Paxman diesels. Intended to be a cheap temporary transition patrol boat until a more permanent craft was built. I believe they were originally intended to be in service 10 years...that was back in the mid 80's and they will probably be around another twenty years. Yes, no helo.
Not a bad boat but not a great one...excellent crews make them better than they really are.
The one thing I remember is hearing the stabilizers slamming back and forth in a following sea. Half of the crew was sick including the XO and the skipper. It was a rough ride. At one point the forward gun came loose and the crew had to secure it. I was in the forward berth and I heard the scuffle. So if that narrows it down let me know. While I thanked the crew when I got off. I'd still like to get in touch with them or the boat. Thanks.