Launceston man Ray Frech was "outraged" when he noticed vehicles with interstate number plates lined up to embark on the Spirit of Tasmania on Wednesday night.
Mr Frech had turned around on the Nullabor Plain to return to Tasmania because of announcements from the state government about coronavirus.
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"When I lined up I noticed a car from Queensland with a camping trailer and other cars with South Australian and Victorian number plates," Mr Frech said.
"It looked like a lot of tourists, I reckon there were a dozen on this trip.
"I thought there is something wrong here, they can't all be essential services.
"I got a bit upset about it because I had driven a lot of kilometres to return.
"Tasmania is probably the safest state because we are an island and it doesn't look like the rules are being enforced."
Mr Frech said no advice was given to passengers about Tasmania's rules as they lined up to embark on the ship in Melbourne.
"When I noticed them driving straight off in Devonport I asked the quarantine officers and they said 'they mightn't all be tourists'," he said.
"They said that they would take a note and check up later on ones looking suspicious."
Mr Frech is in 14 days self isolation.