Three Italian men were arrested by the police as they were caught on a vessel with 55 kilogrammes of cannabis in Marsascala on Thursday, the police said.
The street value of the drug is estimated to be €750,000, the police said in a statement.
The Italians, aged 34, 35 and 54, are all residents in Malta.
On Wednesday, members of the Police Drug Squad, assisted by officers of the Rapid Intervention Unit, descended on Marsascala to seize the vessel as it berthed.
One of the three men jumped into the sea in an attempt to escape, but was caught soon afterwards. A second man who was on the boat was also arrested together with a third man who was waiting on land.
The drugs were found in six sacks.
Searches in the Italian men's residence also yielded cannabis and cocaine.