Issues in order of importance to my pool: Money, sanitation, liability
It has to make financial sense. 3 kayakers displacing 20 swimmers is not going to fly.
Second dirt is a big issue for us. Is there a place to clean out boats?
Liability isn't a big deal as long as there are no other pool users in the water: see money.
Offer to go late at might or early in the morning or on weekends. my pool closes at 5pm on saturdays. That works during the winter well enough.
Write a letter explaining what you want to the pool manager. explain what money it would bring in- if any. Suggest times. have somebody lined up to oversee or host it- preferably an organization, store but possibly a really dedicated person.