In searching one of my primary sources for information on U.S. merchant mariners I find a number of records for (likely) two or more men named Leonard Hudson. None of the records use a middle name or initial. The only other useful differentiation is birth year. One of the men was born in 1905/1906, another was born in 1912/1913. (The records do not contain an exact birth date. Rather the birth year is calculated based on the reported age of the mariner in the record vs. the date of the voyage in question.) In the case of the man born in 1912/1913 there were numerous voyages in 1942 and 1943, a few in 1944 and even 1945. Assuming this was one man, rather than two or more of approximately the same age, it wouldn't leave much time for your father to be in both the Army and Navy as well as the merchant marine during the war. So, anyway, was your father born in either 1905/1906 or 1912/1913?
If the birth years don't fit, or even if they do, I can offer some additional suggestions to address your inquiry.
Ron Carlson, Webmaster
Armed Guard / Merchant Marine website