An insurer may invest in:
(1) Bonds, notes, or other evidences of indebtedness which are secured by mortgages on barges, tugboats, ships, or other shipping vessels if payment of such indebtedness or part thereof is insured by the Secretary of Commerce under the terms of the Federal Ship Mortgage Insurance Act, as amended.
(2) Bonds, notes, or other evidences of indebtedness which are secured by mortgages on barges, tugboats, ships, or other shipping vessels which are under lease or charter party to a solvent institution whose fixed interest obligations, if any, would be eligible investments under s. 625.317 (corporate obligations), and if such lease or charter party is assigned as additional security for such bonds, notes, or other evidences of indebtedness.