To find the whereabouts of a World War II-era merchant ship (not just Liberty ships), see the excellent ConvoyWeb website (http://www.convoyweb.org.uk/hague/index.html) and perform a "SHIP SEARCH" for KENNETH A J MACKENZIE. I did so and found the ship in six convoys in February, March and April 1945, between ports in New Guinea and the Philippines. Since KENNETH A J MACKENZIE was constructed in 1943, that leaves a considerable amount of time unaccounted for. So at the bottom of the list of convoys in which the ship operated there is another link, "To continue the search for OTHER voyages of KENNETH A J MACKENZIE, click here." Following that link will provide a chronological list of the ship's whereabouts throughout its wartime career, including times that the ship sailed independently, i.e., not in convoy and without escort. That list should be more or less comprehensive. March up when your great-uncle served in the ship with that list and you will know where he was during that period.
ConvoyWeb will show the originating and destination ports of a given voyage, inclusive dates, the convoy number if a convoy was involved, and on rare occasion what cargo the ship carried or other notes of interest. There will be no information about the crew.
Ron Carlson, Webmaster
Armed Guard / Merchant Marine website