How to take a SLR camera to take underwater photography, and what are the precautions?

Underwater photography is a very complicated technology, which requires strong professional knowledge and strong physical and diving ability.

SLR underwater photography generally uses a waterproof shell, which is usually a high-end machine with a special waterproof shell. Because there are few people and the technology is difficult, it is expensive, generally two to three times the price of the fuselage.

TB has a 200-300 so-called SLR waterproof sleeve, which can also be waterproof. But will you entrust thousands or even tens of thousands of pieces of equipment to hundreds of pieces of things? I dare not use it anyway.