HMNZS Manawanui was a naval tug which was modified for use as a diving tender by the Royal New Zealand Navy (RNZN).

She was converted to a diving tender in 1953 and served out her time in the RNZN in this role, before being decommissioned in 1978 and sold to the Paeroa Historic Maritime Park.

[citation needed] The vessel was originally built for the United States Navy, and was designated as US Navy tug YLT622, but instead she was transferred to the New Zealand Marine Department who named her Tug 622 and used her to service the large post-war fleet of surplus ships scattered around Waitemata Harbour.

In 1957, she towed the badly damaged patrol launch SDML P3561 off rocks near Rangipukea Island and beached her in a nearby bay.

[citation needed] She was replaced as a diving tender by a specially modified Moa class boat with the same name in 1978.