Learn to control your breathing and self-talk during stress - especially at the pool. Quitting doesn't just happen, there are symptoms that lead to it. Not being able to regulate stress or manage your self-talk are two big ones. Also look up 'AFSPECWAR knots' and learn them. Practice them and use them in unconventional scenarios to solve problems. Pick up 'Building the Elite' a book written by Craig Weller and Jonathan Pope.
Half of this they couldn't do in sea, you don't sink and move soo easy, salt have big effect on eys, waves, sea current, strong wind, temparutre excange, bad visibility, fear of shark, it's much harder.
