The design of a pontoon chosen by the Malta Maritime Authority as a jetty for boats ferrying people to Comino's Blue Lagoon was "unfit for the job" and "an accident waiting to happen", an expert believes.
Speaking to The Times, Peter Llewellyn, a qualified naval architect, explained that the design of the pontoon chosen for the Blue Lagoon was "totally inappropriate".
He said the authority should have chosen a wider pontoon which would have provided greater stability.
The pontoon capsized on July 25, injuring two people, one of whom is mulling taking legal action against the authority for the injuries he suffered. Others, who fell into the water but escaped injury, have claimed compensation from the authority for their damaged mobile phones, digital cameras and other equipment.
Mr Llewellyn said that at the Mġarr marina there were two types of pontoon. Those in the yacht and powerboat section had three flotation chambers and floated at 60cm above the waterline, while those in the fishing boats section had two such chambers and floated at 50cm.
He said the pontoon used at the Blue Lagoon was "almost identical" to the ones found at the fishing boat section of the Mġarr marina. A pontoon which was slightly wider and possibly L-shaped, to provide extra stability, would have been enough to stop it from flipping.
"The design is totally unsuitable for the purpose because the authority knew there would be 50, 60 or 70 people on it at any one time. It was an accident waiting to happen and we are very lucky no one was badly hurt," he said.
Mr Llewellyn said the Blue Lagoon was a crowded and densely populated little bay which combined boats and swimming.
"The concept of putting up something to separate boats from swimmers is good but the design of the pontoon was inappropriate. It wouldn't have cost much more to design a pontoon properly, which would not flip over with many people on it. It's not rocket science but the calculations have to be made."
Mr Llewellyn said 15 people weighed, on average, one ton. A photo taken just a few minutes before the incident shows around 50 people waiting on the pontoon, with a total weight of between three and four tons.
He said the type of pontoon chosen could not take this weight. With five tons it would have been submerged but before actually reaching this point, it would have flipped over if it did not have added stability. Anything that floated lost its stability before it lost buoyancy, he said.
Mr Llewellyn said the chains keeping the pontoon in place were not providing any stability but stopping it moving from side to side and not from flipping over.
Another expert had told The Times that the looseness of one of the chains might have been a factor in the incident.
mxuereb@timesofmalta.com