Manfred Fritz Bajorat, the mummified captain found in his yacht seven years after his death

Not lot times ago, in a mystery ghost boat drifting 40 miles from the shore, was found by two fishermen in the seas of Surigao del Sur province (about 50 miles off Philippines), the body of a mummified captain that still sat in the same seat where he is probably is died. It seems that the man have been trying to make a desperate SOS call, and has been identified as German traveller Manfred Fritz Bajorat.

The mummy, surely preserved by the dry ocean winds, warm temperatures and the salty water, was still sat at a desk near radio equipment on his yacht called Sayo, which was not completely submerged.
With his decomposing body was found also photographs and a creepy letter to his wife, Claudia (divorced?), who died from cancer in 2010.
It is not year clear when exactely he died, and nobody has said seeing him since 2009.
Two fishermen, in the middle of the sea for the weekend, spotted the ghost ship, climbed on board, and before finding the body and photos, saw clothes and tins of food everywhere.
They identified him thanks to paperwork on board, but the cause of death is still unknown, and It’s possible that he had an heart attack.
Also the mast of the boat was broken, and it is not clear if this happened before or after his death. A year before of his probably last voyage, in 2008, he broke up with his wife who abitually travelled with him. It seems that he was a very experienced sailor, and is impossible he would have sailed into a storm. Moreover, on board there was no evidence of another paople, and was found any weapon on the yacht.
How no one can have noticed the disappearance of this man and his boat is a mystery that, with good probability, will never find an answer.