Hi, Don't know if this will help, but one of my ancestors died at sea in 1850. I didn't even know he had died at sea, but I knew he was a sailor and being unable to find a death certificate, I assumed this is how he must have died.
Anyway, by pure chance I tried searching the Trinity House Petitions on Origins. I found that my grt (x5) grandmother had filed a petition and I ordered a copy of it.She filed a petition with Trinity House in order to get a sum of money for her and her children to live on (a modern day pension).
It was invaluable! It gave details of where he died (India), how he died (yellow fever), the names and birth dates of his children, his Widow's name, five of the ships he had sailed on, together with dates and locations of the voyages.
I hope this helps, and good luck
Bex