Captain rhymes with:
kapton, clapton, kapton, knapton, brampton, campton, clapton, clopton, compton, crampton, crompton, crumpton, cumpton, frampton, gupton, hampton, hopton, kapton, kempton, kimpton, knapton, lampton, lipton, lupton, northampton, plimpton, plympton, sharpton, shipton, skipton, southampton, tipton, upton, westhampton
Captain sounds like:
caftan, cape-town, capetown, capitan, capitano, capoten, cappadona, caption, chapoton, chiefdom, chieftain, cohabitation