Superyacht Sinks Like a Stone In the Mediterranean

The 198-foot (60.2-meter) superyacht Yogi sunk under a Force 8 storm in the Mediterranean Sea on Friday. This video, just released today, shows the Hellenic Air Force rescuing the passengers in the middle of the gale.
The boat sunk to the bottom of the sea only seven hours after authorities received the first distress call, 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—the lowest level of gale on the Beaufort Scale—is certainly not the worst weather conditions you can find there.
During a gale, winds blow up to 46 miles per hour (74 kilometers per hour), with "moderately high waves with breaking crests forming spindrift" that can reach 24.6 feet (7.5 meters) high. A strong gale, Force 9, can go up to 54.6mph (88km/h) and result in waves as high as 33 feet (10 meters).
A Force 12 storm is hurricane force, which can result in huge 46-foot waves.

Unclear accident

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. It was constructed with steel and aluminium and it was capable of speeds of up to 16 knots.