October 15...shouldn't be a problem. Barring complications, the sutures come out in a week to two weeks. Often within a month you can't tell where the surgery has been performed. I typically am restoring teeth in the sites of this type of surgery in about 3 months. You probably could return to diving 2-3 weeks after surgery as long as the regulator tabs don't impinge on the soft tissue.
There are typically two ways to do this type of surgery. There is the free gingival graft and the connective tissue graft. The free gingival graft creates a large wound on the palate where the tissue is harvested. This wound cannot be "closed", only covered, and can take a longer time to heal. The tissue donor site can be rather uncomfortable. The actual graft sites involve creating a recipient bed and then placing a block of tissue (from the palate) over the gum bed... next to the teeth with recession and sutured to place. Care must be taken not to disturb the sutured blocks until they "take".
The Connective tissue graft is somewhat different. When harvesting donor tissue from the palate, a small incision is made and a thin sliver of connective tissue is harvested from under the palate skin. This incision is closed with sutures so there is no open wound. The harvested tissue is then woven under the gums between teeth and over the recession areas, then sutured. Again, care must be taken not to disturb the graft. However, the graft is much less bulky and less easily displaced. A variation of this procedure forgoes the palatal tissue harvest. instead, donor tissue from a bottle is used. This technique is often used when there are many sites to be grafted thus creating the need for multiple surgeries just to get enough tissue to cover all sites. Also patients wishing to avoid the harvest surgery may choose to use the bottle.
Harvested tissue is considered the "Gold Standard"... the best way. However, artificial or tissue banked donor material is actually a close second.
Enjoy your dive in October. If you want to show your dentist your regulator, it can't hurt.
Laurence Stein DDS