I lived in s florida for 7 years(boca) before moving back to St. Pete. both areas are great for boating and have similar amenities. I would say s fl has better restaurants. Proximity to the Bahamas and the keys makes it also a lil bit more desireable for boating. I would also favor s florida if you like to spend the scratch. I would move back there in a snap of a finger.
Tampa bay has more affordable waterfront living which is a huge plus for any avid boater. sunsets are way better also on the left coast of florida. I also have family here so that kinda makes it for me. Obviously if you're seriously considering the move you should check out all the areas to see what feels best for you and yours.