for some reason it was not until after the demise of the submarine `` komsomolets '' that the main naval staff came to understand that `` the crews of ships of this type should be manned only by officers and warrant officers , because compulsory-service seamen and petty officers lack the means to adequately master operation of a submarine in such a short time. '' -lsb- . sup -rsb- 6 -lsb- / -rsb-