This is the White-Bellied Storm Petrel. They were absolutely magical to watch as they 'danced' across the waves. It is the smallest of the seabirds that breed at Lord Howe, and are only ever seen on the trip down to Ball's Pyramid.
Lays one egg (in rock crevice) which hatches in 37 days and the chick flies in 80 days.
When feed the WB Storm Petrel hands in the breeze with its feet dangling, pattering the water.