NorthLink employees are in line for a £200 bonus to help them with the cost of living crisis.
Serco, which manages and operates the lifeline ferry service, made the announcement after its half year financial results showed trading profits were up six per cent to £134m.
The £200 payment will be in addition to any pay increases.
Serco chief executive Rupert Soames said: “As a result of the recent surge in inflation we are increasing pay faster than we budgeted and we will be distributing an additional £9m in the coming weeks in one-off payments to all our colleagues outside management grades, recognising the pressure many people, particularly the lower paid, are under at this time.
Serco employs around 57,000 people.