As much as 232 kg of heroin worth Rs 600 crore was seized from the boat which was intercepted on April 20.
"The eight occupants of the boat were not smugglers, but only foot-soldiers," said Atul Chandra Kulkarni, joint commissioner of police (crime).
The Yellow Gate police station here is investigating the case. The investigating officers had already said that the boat's occupants were fishermen and not smugglers.
However, investigations would continue, he said.
Mumbai police have slapped various sections of Narcotic Drugs and Psychotropic Substances (NDPS) Act, IPC and other laws against the eight arrested men.
"They were fishermen who didn't know that their consignment included contraband. They did not know it was heroin," Kulkarni added.
Those arrested include Alibakhsh Allahbakhsh (30), Yunus Sutar (35), G Siddique (40), Gulshan Maulabakhsh (30), Bakhsh Natho (40), Mohmmad Yusuf (40), Mohmmad Ahmed (28) and Maqsood Akhtar. They are currently lodged in Arhtur Road jail here.
