The army and navy have declared war with the battlefield being the stretch of water between Auckland and the Bay of Islands.

Novice crews from both branches of the forces will sail identical training yachts in this year's Coastal Classic.

The winner will be presented with a trophy which is usually up for grabs in an annual night race competition between sail training craft of the navy.

The race starts on the Friday morning of Labour Weekend - the best view as the fleet leaves will be from on top of North Head.