RAISING DIVECAT – PART 1 Loss, relocation and salvage planning
On 6th Feb 2020 my boat Divecat sank while returning from a scuba diving trip to Great Barrier Island. The cause of her sinking will be explained in a future article because it, like many things, was the result of a series of smaller issues that together created the perfect storm. She sank in 43m of water right in the middle of the Firth of Thames, an exposed patch of water known for its fierce tidal stream.
In the hectic days after Divecat’s sinking, I approached several salvage companies and experts about the prospects of recovering her. The consensus was it would be prohibitively expensive, because of her depth and location. None of the companies wanted to take on the job, and the insurance company declined to finance any recovery attempt. And then our first Covid lockdown struck!
Now with plenty myself. I watched many videos of people raising objects from the seabed, and sufficiently scared myself into realising this was not a job to be undertaken lightly. Using numerous heavy lift bags was realistically the only way to do it, but once a sunken object starts to lift it begins a hugely dangerous runaway ascent. Scuba divers know this from Boyle’s Law – any volume of gas underwater expands as it rises. Hence getting just enough lift to move off the bottom would instantly become too much lift as soon as she was just a metre or two higher.
