Lighthouse workers ensuring vessels pass safely through Scottish waters will walk out over a pay dispute for the first time.
Around 40 people employed by the Northern Lighthouse Board (NLB) will stop work at noon on Monday at the start of 24 hours of strike action.
The Unite union, which represents the seafarers, base assistants, cooks and technicians, blamed the UK Government for the dispute, claiming the NLB has been forced to offer a 2% pay increase, while other public sector workers are offered significantly more.