A connector (17) is provided to mount a power generation unit of an underwater power generator to a base assembly. The connector comprises (17) a lower connector portion (72) having a stem (62) projecting upwardly and having a tapering profile and an upper connector portion (70) having an inwardly and upwardly extending recess (60). At least one generally cylindrical pin (61) extends radially inwardly into the recess (60) and at least one groove (64) is formed in the stem (62). The groove (64) is configured to allow the pin (61) to travel along the groove (64) as the stem (62) is axially inserted into the recess (60).