AWS D3.6M – UNDERWATER WELDING CODE

This code covers the requirements for welding structures or components under the surface of water. It includes welding in both dry and wet environments. Clauses 1 through 8 constitute the general requirements for underwater welding, while clauses 9 through 11 contain the special requirements applicable to three individual classes of weld as follows:
Class A—Comparable to above-water welding
Class B—For less critical applications
Class O—To meet the requirements of another designated code or specification

Go to AWS AWS D3.6M at AWS.org