Scillonian III celebrates fourth year as UK’s leading wildlife-watching ferry route
Scillonian III had barely left the shelter of Penzance Harbour when a smooth grey rostrum broke the surface, catching the early light before sliding back beneath the water. On the deck above, a volunteer surveyor from ORCA, the leading marine conservation charity, smiled as they logged the first sighting of the day.
Common dolphins
Porpoise
Across seven months of surveying, the data gathered from Scillonian III revealed a crossing brimming with marine life. 27 volunteers recorded nearly 600 animals along the 28-mile crossing to St Mary’s, a remarkable 72% increase on the previous year.
Since 2009, trained ORCA surveyors have boarded the ferry from March to October. Their work helps scientists understand how whales, dolphins, porpoises, seals and fish use this busy stretch of water and how those patterns are changing.
Cory’s shearwater bird
Fulmar
Across 14 surveys covering 1,727km, observers logged eight different species, one more than in 2024. It’s no wonder that this route has been named as the UK’s top ferry route for marine wildlife for a fourth consecutive year.
Some days were especially memorable:
- 137 individual animals recorded during a single August survey, and
- six species on one September crossing, including harbour porpoise, common and risso’s dolphins, bottlenose dolphins, grey seals and tuna.
It was the common dolphins that dominated the season with 450 individuals recorded, almost double last year’s count.
For the volunteers, the surge was both thrilling and scientifically significant. Such changes suggest the dolphins may be shifting their distribution, perhaps following changing patterns of prey. Climate research has hinted at this too: warming oceans are affecting the life cycles and locations of key species in the English Channel and Western approaches, with ripple effects through the food chain.
Risso’s dolphins also made a strong showing, with 11 individuals recorded. Their tall dorsal fins and drew excitement on deck each time one surfaced.
Common dolphin
For ORCA’s Director of Programmes, Lucy Babey, the season was exceptional.
“We had an incredible season surveying on board Scillonian III this year,” she said. “For nearly 16 years, teams of highly trained volunteer marine mammal surveyors have conducted scientific surveys for marine wildlife from Scillonian III. This year-on-year continued monitoring by ORCA enables trends and shifts in cetacean distribution being reported on in real-time – essential for cetacean conservation.
“We are so proud to work with the Isles of Scilly Travel on the crossing between Penzance and St Mary‘s, and we can’t wait to be back on board in 2026.”
Group Marketing and Communications Manager, Sharon Sandercock, from Isles of Scilly Steamship Group, reflects on the magic that brings passengers back year after year:
“The Isles of Scilly is a breathtaking destination, and that beauty begins the moment you set sail. The crossing has become one of the richest and most accessible wildlife-watching corridors in the country, giving passengers a rare opportunity to witness some of the UK’s most spectacular marine life on their journey to the islands.
“We’re proud to welcome ORCA’s dedicated volunteers aboard each season and always look forward to their annual findings. Supporting their important work is something we value deeply, and receiving this accolade for a fourth time confirms just how special this route is for both wildlife and the people who travel it.”
As the season closed and the autumn weather rolled in, the surveyors tucked away their notepads and binoculars for another year. If 2025 is anything to go by, the waters between mainland Cornwall and St Mary’s remain a dynamic and valuable route for spotting marine wildlife.