As a kid growing up near SF in the 80's and 90's, I had the true pleasure of being a member of the US Navy League Cadets and US Naval Sea Cadets that drilled on Treasure Island. The unit was there for a VERY long time, and just before I left it celebrated 50 years of training the local youth.
The Cowell Division, which was renamed the Carl Vinson Division and TS San Francisco was a very common sight on the weekends at TI, drilling in Bldg 2 and around the base. During the summer the base swarmed with hundreds of cadets in uniform, learning about our military, and doing an awful lot of marching.
What a magical place, that island. It was a "Second Home" to many of us, and it is sincerely missed.
I hope that someday soon the base will be utilized and appreciated to the utmost, as there is unlimited potential there for so much good to come from it.