Underwater photos

You might get one or two, before water intrusion possibly destroys your phone, which then won't be covered under warranty and will require you replace the phone.

So, I'd say no. It's most unwise to take a device which is NOT waterproof under water.

There are some cases on the market that proport to make your iPhone waterproof thus able to use underwater.This premise is similar to camera housings used for underwater photography.I believe that something as valuable to everyday life as your iPhone there are much better choices.Get yourself an inexpensive underwater camera and if you find you enjoy underwater photography as do I treat yourself to a camera made explicitly for that purpose.I would not trust my iPhone to any of the “cases” marketed for underwater photography at this point in time.Be well.

Kspagnola wrote:

Can I take underwater photos with an IPhone 11 Pro Max?

Although water resistant to a degree, no iPhone is an underwater device.

It is not suggested you try.