The 500 crewmembers on board the frigate HMCS Halifax and the destroyer HMCS Athabaskan still aren't sure exactly how they will get aid to the people of Haiti, which was devastated by Tuesday's massive earthquake, says the head of the Canadian task group.

Cmdr. Art McDonald said Friday that the Canadians want to deliver aid, but not at any cost.

"What I want to do is make sure that we don't jeopardize any Canadian lives while we're saving Haitian lives. But we will be able to do both with a proper threat assessment," he said on board the Athabaskan.

"I don't want to deliver aid at the barrel of a gun, but we will bring aid in the most effective means possible."

McDonald made the comments in the wake of news that lawlessness is growing in Haiti with the collapse of its police force and legal system.

The navy is considering staying at anchor rather than tying up at a wharf in Haiti, McDonald said. That way they could send work parties ashore in small boats that could be better protected.

The sailors and airmen on board the two ships are being inoculated for typhoid. The navy's biggest worry is malaria, and it will begin administering anti-malarial medications once it decides whether personnel will go ashore in Haiti.

Early Friday afternoon the ships were about 200 nautical miles off the coast of Norfolk, Va.

They steamed out of Halifax harbour Thursday afternoon, with a sendoff from Defence Minister Peter MacKay and family members.

Both ships are loaded with first-aid kits, a Sea King helicopter and other supplies and equipment such as power generators, chainsaws and the Jaws of Life.

They are expected to arrive off Haiti on Monday.