In a beach town, salt air wears on water heaters year after year, on the fittings, the connections and the tank itself. So the thing that matters is knowing the warning signs and acting on them while they're still warnings.
Watch for water that's hot but not as hot as before, hot water that runs out early, or a pilot that keeps going out. Rust at the base, moisture on the floor and corrosion on the fittings are warning signs too. Any one of those is the time to call, while there's room to weigh a repair against the tank's age and, if it's time, choose a replacement with the coast in mind.
Call at the first sign, hear a straight read in plain English and decide for yourself. Beach air is hard on equipment, so it helps to catch problems while you still have time to choose.