Amazon has the Lifeproof FRĒ Series Waterproof Case for iPhone SE (2nd gen - 2020) and iPhone 8/7 (Not Plus) (77-56788, Night Lite) for $27 with free shipping. Best Buy has it for iPhone 7 Plus and 8 Plus (77-56981) for the same price.

Shock-proof and fully submergible to 66'/2 m for 1 hour.