Hot Pursuit - Jeaneau Sunfast 3200

Hot Pursuit: Keel and Mast Alignment Survey, Cowes

Following a grounding during a race in the Solent, Hot Pursuit, a Cowes-based Jeanneau Sun Fast 3200 racing yacht, suffered substantial damage to her keel. The yacht was lifted ashore, the keel removed and the keel box rebuilt before the keel was reinstalled.

The attending surveyor subsequently raised concerns about its alignment. Viewed from astern, the keel appeared to angle towards port. Checks using a tape measure had proved inconclusive, so NautiData was asked to investigate using 3D laser scanning.

Hot Pursuit’s twin rudders made it difficult to establish a central reference by eye. Sighting past the propeller assembly towards the keel suggested something was wrong, but this relied on the assumption that the propeller assembly itself was on the yacht’s centreline.

Reliable measurements first required a stable boat. Drawing on our sailing experience, we arranged for the yacht to be lifted and positioned behind an industrial building in the boatyard to shelter her from the wind. Lines from both sides of the bow and stern secured her to the travel lift, helping minimise movement throughout the survey.

We captured approximately 40 laser scans around the exterior and inside the yacht. These were combined into a detailed 3D point cloud, allowing us to examine the relationship between the hull, keel and rig within a single measured dataset.

The survey resolved the concern. The keel was correctly aligned, but the propeller assembly was offset towards starboard, a detail that had not previously been recognised by those investigating the problem. Sighting past this offset assembly towards the keel had created the misleading impression that the keel angled towards port.

Our measured plan and stern views showed the alignment against centreline references, supported by a longitudinal section through the yacht. This provided clear evidence to explain what visual checks and tape measurements had been unable to resolve.

We also checked the relationship between the keel’s trailing edge and the mast’s mainsail track along the height of the rig. The survey confirmed the mast was straight, without local kinks, and provided measurements of mast rake and pre-bend for the sailmaker to inform the design of a new mainsail.

Later that same year, Hot Pursuit went on to win at Cowes Week. We were proud to have played a part in her return to competitive racing, combining practical sailing knowledge with precise survey data to resolve concerns about her keel alignment.