Which statement concerning GMDSS Radio Operator requirements is FALSE（）.

A. Each compulsory vessel must carry at least two licensed GMDSS Radio Operators at all times while at sea
B. Each compulsory vessel must carry at least two licensed Radio Operators at all times while at sea and may elect to carry a GMDSS Radio Maintainer as well
Communications involving safety of life at sea do not have to be logged as long as the compulsory vessel was not involved in such communications
D. While at sea，adjustments to，and the maintaining of，GMDSS equipment may be performed by the GMDSS Radio operator as long as the work is supervised by an onboard licensed GMDSS Radio Maintainer