I personally don''t like the looks of Cetol. For longevity and ease of application, check reports by Practical Sailor on finishing exterior teak. I personally like Bristol Finish, a two-part finish that is applied in about 6+ coats, one hour apart. It looks very much like a traditional
varnish and lasts quite well, even in the Florida sun.
Before commiting to Cetol, do a test on a nice piece of teak. Try Cetol on one half, and a traditional spar
varnish on the other. While you would not use the spar
varnish for the final coat, it will allow you to see the differences. If you decide you like Cetol, go ahead. Otherwise, research some alternatives. Cetol is a pain to remove once applied.