FWIW, my series 6 did not survive a drop into a cenote in mexico. It was NOT a deep dive.

Its water resistant. Not water proof. YMMV.

On vacation in Mexico, I got to drop from a zipline into a cenote. Great experience for me. However, the Apple Series 6 watch did NOT survive the experience. Perhaps it was the nature of the impact into the water. Or perhaps it was the mineralized water. Who knows. Bottom line. Its water resistant. At best. Not water proof.

I recently replaced my broken series 6 with the same basic model from back market. Battery life looks really good so far. Was just over 200 but I bet they are cheaper now as this was before the newest models launched.