Can i use my apple watch (series 2) in salt water (sea)?

Apple Watch Series 2 and Apple Watch Series 3 may be used for shallow water activities like swimming in a pool or ocean.

From:

About Apple Watch water resistance - Apple Support

It also says:

Apple Watch should be cleaned with fresh water and dried with a lint free-cloth if it comes in contact with anything other than fresh water.

Hi

Apple Watch Series 2 models can be worn when shallow water swimming, including in salt water / the ocean.

After wearing Apple Watch Series 2 in the ocean, be sure to clean it by gently rinsing it with warm tap water. The watch and band should be dried using a soft, lint-free cloth.

Keep in mind that Apple also advises cleaning your Apple Watch if it comes into contact with any substances that may cause damage. Examples include contact with sand.

Note also that leather and stainless steel bands are not water resistant, so should not be worn in the ocean.

More information and instructions:

• About Apple Watch water resistance - Apple Support
• Important handling information