(a) All construction-differential subsidy agreements and mortgages relative to vessels covered in §289.2(a) shall provide, wherever possible, that the Maritime Administrator may, in his discretion, require the owner to insure, with commercial underwriters, the interest of the United States.

(b) All future construction-differential subsidy agreements and future operating subsidy agreements shall require that owners insure vessels covered in §289.2 (a) and (d) in amounts acceptable to the Maritime Administration.