Get your own insurance; do not teach swimming without it. Federal or state law does not require insurance; it is possible individual counties or cities might, and certainly, any given pool has the right to require anyone teaching there to insurance. Therefore, you are not globally or always required to have insurance, but might be required to do so in individual cases. However, even when you legally could teach without insurance, you should not. The pool's insurnace does NOT cover you; it covers only the pool, which is the insured and the one buying/paying for it. They buy insurance to protect themselves, not other people. If you are personally sued, therefore, you need your own insurance or else you will be paying out of pocket--and if a child is injured, the judgment against you (amount you could be required to pay) could be very, very large.