Its 360 residents have been without fire cover since November last year because the two men's beards prevent them from wearing breathing apparatus in an emergency.
Fire crews from Lerwick will be ferried across the harbour should a fire break out on Bressay, while officers from the town have been handing out fire prevention advice to residents.
The pair's stubbornness has been condemned by Shetland community safety board vice-chairman Allison Duncan, who has been trying without success to persuade them to lose their facial hair.
"To know that a couple of firefighters are putting the safety of Bressay people at risk is absolutely crazy," he said. "There's elderly, frail people, there could be a car accident, there was a fire at the back end of Bressay. I've done my utmost to get them to see sense and get the appliance back on the run in the interests of the Bressay people."