Seafarers working for the UK's Trinity House have staged their first strike in more than 500 years.
The crews help maintain 11,000 aids to navigation in UK waters.
They are demonstrating over pay at the Trinity House office in Harwich, Essex, on Wednesday.
The Unite union has 34 members working on three lighthouse tenders.
They have already taken a day’s strike action earlier this month in their dispute over seven years of below-inflation pay rises, or no increases at all, the union said.
