He served for twenty years in various vessels of the Royal Fleet Auxiliary. Highlights of his time were being the first RFA officer to attend the Long Navigation  Course (topping the sea time component), and also beating the entire Naval fleet in a midshipmen’s cup race in his very early years.

Following RFA service he went on to become a pilot in Portsmouth where he served for ten years, as well being a ship handling lecturer with Warsash Maritime Academy.  A decade followed as pilotage manager and later Deputy Chief Executive of the Harwich Haven Authority.  During this time he oversaw introduction of international standards of VTS in planning potential entry and handling  of  very large container ships in the Port of Felixstowe.

In the UK he was Chairman of the BPA / UKMPG Joint Marine & Pilotage Committee. In addition he was a Council Member of UKHMA and served on the papers’ committee of the IHMA.

In 2008 he moved to Australia and was appointed General Manager of Marine and Navigation Services and Harbour Master at the Port of Melbourne. Over the next 13 years David had two stints as Port of Melbourne Harbour Master and also held the role at the Port of Portland, Victoria. In May 2019 with the Victoria Regional Channels Authority he was appointed Harbour Master and Marine Manager of the Port of Geelong, Victoria.

He brought with him a wealth of experience as seagoing officer and harbour master with the commitment to the highest standard of safety of these significant ports of Australia.  With the Port of Melbourne Corporation he helped manage operations during channel deepening works with the resultant implementation of  port operating guidelines. He retired in 2021.

He owned North & Trew Marine Consultancy with his wife Joanna.

David passionately and effectively championed the improvement of safety standards and port resource management, and was a willing mentor for younger mariners – a number of whom now hold harbour master roles.  He was Branch Master for the Melbourne branch of the Company of Master Mariners, and the sole remaining Younger Brother of Trinity House in Australia. He was Past-Master of the Melbourne Branch of the Company of Master Mariners of Australia. He served on the PIANC Board of Australia from 2008 to 2010.

He was also a Younger Brother of Trinity House being admitted in 2005.