Can cruise ship company force employees to take flu shots?

I am going to work on a cruise ship soon. After reading a lot about the new H1N1 vaccine I am not willing to take the flu shot that is going to be thrown at me as soon as it is available. The company says that this coming vaccination is mandatory.

According to company Code of Conduct disciplinary action can be taken under the line that reads "Failure to adhere to the instructions of the Medical Department in relation to the treatment or management of any infectious / contagious illnesses, or submit to vaccination or treatment as required for public health.”

I know in the States one may sign a waiver form from one's family physician. However the ship sails in the open seas. Is there such form in Canada and does that apply to cruise ship sailing out of North American territories?

Thanks!