World War II Merchant Mariner Service Act - Directs the Secretary of Homeland Security (DHS) to consider certain methods for verifying that an individual performed honorable service as a member of the merchant marine during the period beginning on December 7, 1941, and ending on December 31, 1946, for purposes of eligibility for veterans' benefits under the GI Bill Improvement Act of 1977. Requires such methods to include Social Security Administration (SSA) records and validated testimony in the case of the absence of Coast Guard shipping or discharge forms, ship logbooks, or other official employment records.
Requires the Secretary to recognize masters of seagoing vessels or other command officers who were authorized to document an individual for purposes of hiring for the merchant marine or discharge therefrom, when determining whether to recognize service allegedly performed during such period.