Man 'saw wave hit boat, sought help'

Police are appealing for a man who witnessed a fatal boat accident in southern Sydney yesterday afternoon to come forward.

The runabout was manoeuvring at the entrance to Port Hacking when it was hit by a wave about 1:30pm (AEST) yesterday.

The impact caused the boat to capsize, throwing two men into the water.

A 52-year-old man died while another man, also in his 50s, suffered hypothermia.