Blue Cheer surfboards age

I just found an old “Blue Cheer Surfboards” single fin. About 6’5", rounded pin, real thick (3"+) Numbered # 425. Anybody know how old this is? No leash plug or hole. Looks like the original fin and box. Can’t wait to get it cleaned up and see how it rides. Real down rails too. Hmm…

late 70’s early 80’s shaped probably by tim phares. i can ask him as he stops by the shop often.

Wow, does that ever bring back memories. Jay Stone started Blue Cheer, taking over the old Hobie Shop in WLA/Santa Monica on Wilshire Blvd after Terry Lucoff and Robbie Dick started Natural Progression. This would have happened about 70 or so. No idea on the actual age of the board. You could call Blue Cheer dive shop in SaMo and see if Jay is still around. he might be able to tell you.