The UK's first purpose-built floating ambulance is to start serving residents in the Isles of Scilly.
The new floating ambulance will be based in St Mary's
The £260,000 catamaran Star of Life will travel at speeds of up to 25 knots from its base at St Mary's to four other islands.
It will transport patients from Bryher, Tresco, St Martin's and St Agnes to hospital on St Mary's in centrally-heated comfort.
The state-of-the-art 36 ft catamaran is equipped with a defibrillator,
emergency life support kit, oxygen and pain-relief drugs.
It will also transport doctors, midwives and health visitors from St Mary's to the sparsely-inhabited off-islands.
The Westcountry Ambulance vessel replaces the 27 ft Santa Warna which travelled at a maximum speed of eight knots and had only a tarpaulin cover to keep patients dry.
A charter boat has been used for the past 18 months because the Santa Warna was deemed unfit for use.
Tony Smith, ambulance co-ordinator for the Isles of Scilly, said the new jet-propelled vessel could also be used to transport patients to the Cornish mainland 28 miles away.
"I have to make the journey by sea two to three times a year when we have thick fog which means the helicopter can't get across," he said.
The Star of Life is due to leave Plymouth for St Mary's on Saturday, where it will go into immediate service.
Westcountry Ambulance chief executive Michael Willis said the new craft would improve patients' comfort.
"This launch is a huge leap forward in care for patients on the Isles of
Scilly," he said.
The ambulance will be permanently staffed by an ambulance technician and a coxswain.