How did it all begin?
In the world of sailing, truly incredible stories can surprise even the most experienced sailors. The story of the yacht Polbream is a bright example of this. Imagine: a 37-foot yacht traveled 150 miles at sea, losing its keel, and no one suspected anything! Neither the captain nor the passengers realized that their vessel had lost one of the main elements of safety. This article tells the tale of what happened to Polbream, the circumstances that contributed to such a remarkable incident, and the lessons that can be learned from it.
Course of Events
Almost an unbelievable story unfolded around the yacht Polbream, which lost its keel but managed to complete three cruising trips before a serious problem was discovered. Polbream, a Jeanneau Sun Odyssey 37 model built in 2001, during a week-long yacht charter in the River Helford, experienced strong heeling (sudden tilt) due to a 5-beaufort wind. The frightened crew lowered the sails and switched to the engine, heading towards Falmouth. "We thought we had steering issues," the captain of the family crew later recalled. The charter company from Falmouth provided them with another yacht so they could continue their journey. Meanwhile, Polbream was lifted ashore, and everyone was astonished to discover that the keel had disappeared.
Prior to this incident, the yacht had successfully completed three trips in this condition – one towards the Scilly Islands, another to Plymouth, and the third along the River Helford.
How Did the Keel-less Yacht Cover 150 Miles Without Capsizing?
Questions arose instantly:
- How could a vessel travel such a distance without a keel, without losing stability?
- How did the captain and crew not notice a significant deterioration in stability after losing the ballast?
- Why did no one notice that the yacht was sailing higher than usual?
My task was to compile a report for the insurance company regarding Polbream, explaining the reasons for the loss of the keel and analyzing the incident.
Incident Progress
In August, Polbream was chartered to an experienced captain who trained at the captain's school and holds types of boat licences with 30 years of experience. He directed the yacht to the Scilly Islands, and already on the return trip, the incident occurred. According to his impeccable experience, there had been no prior incidents of grounding or dangerous situations. On August 14th, while moving under engine power at 4–5 knots through the North Channel near Old Grimsby, the yacht slightly lifted, as if it had brushed the seabed. No one noticed a significant drop in speed. The crew checked the engine room and, finding no flooding or structural damage, continued towards Falmouth under the influence of a 12-knot following wind and with the use of the headsail.
Later, the captain noted that steering became somewhat more difficult, but the transition occurred without serious incidents – except for the area with choppy waves near Lizard Point. Upon returning Polbream to the charter company, the captain did not report the incident. He later admitted that he had probably underestimated the significance of the light contact with the bottom, as there were no external signs of damage, and the impact was quite soft.
Discovery of the Keel Loss
When divers later discovered and retrieved the two-ton keel from the seabed, a clear impact mark was visible near the front edge at mid-height. The keel did not come off due to corrosion of the bolts, but rather because the impact was centered directly on the yacht’s center of gravity, causing the bolts to snap under lateral force instantly. Since the force was applied directly to the center of mass, there was no leverage effect capable of lowering the bow of the vessel. If there had been significant slowing or a lowering of the bow, the load would have been distributed over a longer period, which could have led to visible hull damage. However, the instantaneous impact caused such extreme stress that the bolts sheared off immediately.
Many wondered how the crew did not notice that the keel had come off. According to the captain, the vessel behaved as if it had merely brushed against a minor underwater obstacle. In reality, the absence of the keel resulted in a slight rise in the hull – the yacht became lighter and had a reduced draft.
The Role of Luck and Design Features
Every vessel has a certain form stability, which depends on the beam of the hull. The Jeanneau Sun Odyssey 37 is a fairly spacious yacht, which provides it with a certain degree of stability. In standard configuration with a keel, this type of vessel maintains stability even when heeling up to 120 degrees. Of course, losing the keel significantly reduces stability, but it remains sufficient to prevent capsizing in calm conditions.
In this story, luck played a crucial role. For most of the route, the yacht sailed with the wind, and during the final leg in the Helford River, there was a strong surge. The wide hull, full water tanks (which acted as ballast), the weight of the engine, and the massive rudder provided the minimum necessary stability to prevent capsizing under favorable conditions.
Why Did No One Notice the Loss of the Keel?
Some sailors mistakenly believe that low stability is associated with high speed, thinking that slow movement is always safer. Despite noticeable difficulties in handling and an increased rolling period due to the missing keel, some crew members may have mistaken this for comfortable vessel behavior rather than a worrying sign.
It is also worth noting that when the yacht is docked, its waterline is often not visible from either the dock or the deck. In this case, the difference in draft was only about 10 cm (4 inches) – a subtle detail that could only have been noticed upon close inspection.
Conclusions and Lessons
The incident with Polbream highlights important lessons for yacht owners and sailors:
- After any contact with the bottom, a thorough check of the keel and internal hull should be conducted. One should never consider a "minor" touch harmless.
- Any impact with an underwater obstacle, especially for yachts with a deep keel, can lead to serious structural damage.
- Over time, elements such as keels and hulls can weaken due to material fatigue, even if they appear intact at first glance.
- Repeated, seemingly minor touches to the bottom can accumulate hidden damage, ultimately leading to catastrophic consequences.
Technical Analysis
When divers discovered the keel stuck on an underwater reef, it was immediately brought in for examination. All three keel attachment bolts were cut off flush with the yacht's fiberglass hull. The remaining fragments of the bolts were sent to Hampshire for metallurgical analysis. The type of deformation and the nature of the break confirmed that the damage was caused by a direct impact with a solid underwater object – corrosion did not play a role here. The bolts met the specifications and strength requirements outlined in the yacht's design.
This case serves as a harsh reminder of how critically important the keel is to the integrity of the yacht and how easily structural damage can be overlooked – until it is too late. For more insights, visit our yachting blog.