Keith:
I understand this as:
Your #
HIN:TDL31146I687
TDL = Traditional Watercraft Inc. TDL the incorporated name for Island Packet Yachts
31 = Model
146 = You hull number in the line and order of build. This is hull # 146 of the 31 model
I = The ninth month of the calendar year. September she was built
6 = ?? I think is the day of the month
87 = The year
So I read this as your hull was made on September 6, 1987 that is OTTER's Birthday!
Hayden
