In 1786, Waterhouse joined as a
midshipman after
Cumberland House recommended him to Governor
Arthur Phillip. Waterhouse sailed to Australia with the
First Fleet and helped establish the settlement at
Sydney Cove. On 2 October 1788,
Sirius was sent to pick up supplies from
Cape of Good Hope, completing a circumnavigation on its return in March 1789. When the ship's third Lieutenant George Maxwell's behaviour became increasingly erratic and bizarre, he was discharged and Waterhouse was promoted to acting third Lieutenant. Waterhouse was a member of the crew when
Sirius was wrecked off
Norfolk Island. He returned to
Sydney Cove on to become an aide to Governor Phillip. Waterhouse was present at the whale feast with
Indigenous people at
Manly Cove; after Phillip was speared in the shoulder, Waterhouse snapped off the shaft and helped the Governor return to the boats. In 1791, Waterhouse returned to England with the rest of the crew of the
Sirius on the
Waaksamheyd. ==French Revolution==