The Stena Immaculate, with a crew of 23, was transporting more than 220,000 barrels of aviation fuel from Greece to the UK.
The Solong, with a 14-strong crew, was carrying mainly alcoholic spirits and some hazardous substances, including empty but unclean sodium cyanide containers.
Speaking earlier following the sentencing, senior investigating officer Det Ch Supt Craig Nicholson, of Humberside Police, said: “Motin completely failed in this duty as a captain, causing the death of one of his own crew and endangering the remaining lives of the crews of both vessels.
“Motin has shown no remorse at any stage of the investigation or court proceedings, and even though he has now been sentenced and held accountable for his crimes, it will not bring Mark back.
“I sincerely hope today’s outcome offers Mark’s family some measure of solace and my thoughts remain with them today.”