The Collaborative International Dictionary of English v.0.48:

Hoyman \Hoy"man\, n.; pl. Hoymen.
   One who navigates a hoy.
   [1913 Webster]

         A common hoyman to carry goods by water for hire.
                                                  --Hobart.
   [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

HOYMAN. The master or captain of a hoy.
     2. Hoymen are liable as common carriers. Story, Bailm. Sec. 496.