By the book; sympathetic industrial action is not protected for that reason alone

The existence of what may be considered to be a legitimate concern which prompts the taking of industrial action does not render that action to be protected industrial action. Further, industrial action does not become protected industrial action because of circumstances where there may be personal psychological impacts arising from the continuation of work in accordance with the manner that work is customarily performed and without any form of restriction, limitation or delay upon the performance of work. The prospect of some adverse physiological condition does not translate into a reasonable concern about an imminent risk to health and safety.
Although I may personally have great sympathy for the crew of the Alexander Spirit, the predicament that these individuals face is, in essence, a predicament that is broadly shared by many other Australian workers. The prospect of sailing the Alexander Spirit to Singapore may, for example, be contemplated in similar fashion to those vehicle manufacturing workers who assemble the final Falcon, Commodore and Camry.
Consequently, the industrial action in this instance satisfies the definition of industrial action and it is not protected industrial action.
Teekay Shipping (Australia) Pty Ltd v Maritime Union of Australia (2015) FWC 4498 delivered 7 July 2015 per Cambridge C

****An appeal against this decision was unanimously rejected by a Full Bench on 10 July, even though leave to appeal was granted