The 60.2m superyacht Yogi sunk under a Force 8 storm in the Mediterranean Sea. This video shows the Hellenic Air Force rescuing the passengers in the middle of the gale. It took only seven hours to sink after the authorities got the first mayday, according to the builder Mehmet Karabeyoglu:
What I find surprising is that [from] the first mayday call to the boat sinking was nearly seven hours. They had power as you can see lights on [in the video shot by the Hellenic rescue team].
What we can see is that she survived seven hours without turning over. So this is enough reason for us to believe she could have been saved — although we are not blaming anyone. There was a Force 8 so the weather made things difficult, but she did not sink due to the weather.
Contrary to popular belief, the Mediterranean can be extremely dangerous to navigate, but a Force 8 storm is certainly not the worst weather conditions you can find there.
During a gale, winds blow up to 74km/h, with "moderately high waves with breaking crests forming spindrift" that can reach 7.5m high. A strong gale, Force 9, can go up to 88km/h and result in waves as high as 10m.
According to the modern Beaufort scale, you can go up to Force 12, hurricane force. This results in huge 14m waves.
There's no clear reason for the sinking yet. According to the eight French crewmen who were rescued, "it was mechanical failure, that one engine overheated, and broke the exhaust bellows." According to Karabeyoglu, Yogi "was just repainted, but we did no work in the engine room as it was perfect. No mechanical work other than routine service of the Cat engines. Perhaps they took bad fuel when they refueled in Istanbul."
The superyacht was designed by Jean Guy Verges, and constructed with steel and aluminium. It was capable of speeds of up to 16 knots.
While Karabeyoglu doesn't want to blame anyone -- after all, Captain Schettino is still under arrest -- he claims that she could have been saved from sinking. [Boat International, Hellenic Air Force via Nauta (In Spanish)]