An eel! That actually makes good sense.
True story here...my dad was in the Navy during the Korean War on the USS Wisconson. Told me one day in the N. Atlantic men were calling everyone they could get onto the deck to see a “sea monster”. It was (according to my dad) dark, muddy brown in color...about 3 ft thick with a head “like a snake” and was probably close to 50 ft long as the men judged. Dad said about 100 men witnessed this and they ALL simply attributed it to some deep sea snake or eel. So neat you said that. Could be a great-grandaddy eel that was somehow able to grow to that huge proportion.
Forgot to ping you to #35