The Flying Christine III is currently out of service after a mechanical fault was found with the vessel.
The marine ambulance was on route to the Isle of Wight for maintenance following its recent refit, when the issue became apparent, just north of Alderney, early on Saturday morning.
The boat crew made the decision to return to Alderney, arriving safely at Braye Harbour shortly after 09:00.
The vessel was seen being lifted out of the water on to dry land so she could be inspected.
Work has continued to assess and identify the extent of the problem, to try and work out how much longer she may be out of action for.
A spokesperson for the Ambulance and Rescue Service – which uses the charitably funded marine ambulance to help patients across the Bailiwick – said, as the vessel was intended to be out of action for maintenance anyway, there was already a plan in place to cover her.
That plan was enacted over the weekend with a call out to Herm on Saturday morning.
“Long standing contingency plans were already in place, to ensure a resilient medical response for the islands of the Bailiwick, which includes use of a number of relief vessels,” explained the spokesperson.
“Those plans have already been enacted, with the Bailiwick Chief deployed to Herm this morning, with a paramedic crew onboard, for an injured patient requiring treatment and transfer to Guernsey.
“We would like to thank the operators of the relief vessels for offering their services to ensure the vital lifeline marine ambulance provision can be maintained.”