Dating a hobie surfboard

Can anyone help me to date my hobie surfboard that I recently won on an online auction? The serial # is 9621. Thanks

“Date” your surfboard? man… surfers are sick creatures. I thought I had it bad…

How old did the seller say it is? How old do you think it is? Serial numbers are not much help. Very few labels kept accurate records and some even started new sequences.

Got any photos? I mean good ,clear, worthwhile shots of the top, bottom, fin, etc…