[Putershark]

Oh your welcome Vic ,
I also found this read from Chevron (all I run in my Outboard) on long term fuel storage that may help explain some of the needs or not for using such additives in your tank...

http://www.chevron.com/products/prod...term_gasoline/

And I would denote the statement from them that fuel can be stored for 1 year under the right conditions. So you may not even need to use such additives in your boat tank pending of course, how often you run your boat and the local weather .