As marine conservation charity ORCA celebrates its 25th anniversary this year, Isles of Scilly Travel is proud to reflect on a partnership that has helped reveal the extraordinary marine life found along the UK’s most wildlife-rich ferry routes.
Since 2009, ORCA’s marine mammal surveyors have travelled on board Scillonian III, collecting valuable data on the waters between Penzance and St Mary’s. What began as a collaboration to support marine conservation has grown into a long-standing partnership that continues to contribute important insights into the wildlife that calls these waters home.
Over the past 17 years, ORCA volunteers have completed 207 surveys, covering an impressive 25,461 kilometres. During that time, 621 marine mammal surveyor placements have been offered on the route, many of them filled by trained volunteers from Cornwall and the south west.
The surveys have recorded 1,787 animals from 17 species, highlighting the diversity of the marine environment around the Isles of Scilly. Sightings have included whales, dolphins, porpoises, sharks, sunfish, tuna, turtles and seals, underlining the route’s importance as a corridor for a wide range of marine wildlife.
The most frequently recorded species have been:
- Common dolphin: 839 individuals (46% of all sightings)
- Harbour porpoise: 378 individuals (21%)
- Grey seal: 129 individuals (7%)
Stand out wildlife encounters
In September 2012, surveyors recorded an incredible super pod of 120 common dolphins, creating a spectacular display alongside the ship.
In 2016, ORCA teams were fortunate enough to witness John Coe and Aquarius, the last two members of the UK’s only known resident orca pod.
The route has also produced sightings of minke whales, long-finned pilot whales Risso’s dolphins, fin whale, humpback whale, ocean sunfish, blue shark, tuna and even a leatherback turtle.
Excitingly, basking sharks, which had not been recorded from the route since 2022, have once again been sighted by ORCA teams aboard Scillonian III this year.
A dramatic feeding frenzy was observed in 2025, when 15 dolphins were seen herding fish into bait balls while gannets plunge-dived from above to snatch prey from the surface. With gannets able to hit the water at speeds of up to 60mph, this created a spectacular wildlife event, witnessed by passengers on Scillonian III.
Passengers are often treated to common dolphins bow-riding alongside the ship. Surfing the pressure waves created by Scillonian III at speeds of up to 35mph, these playful marine mammals regularly provide unforgettable moments for everyone on board.
Supporting marine conservation
The information collected by ORCA surveyors contributes to a growing understanding of marine species distribution and helps support efforts to protect the UK’s marine environment.
As ORCA marks its 25th anniversary, Isles of Scilly Travel is proud to celebrate a partnership that has been running since 2009 and has generated a remarkable wildlife record for the route.
Isles of Scilly Steamship Group chief executive, Stuart Reid, said:
“For more than 15 years, we have been proud to support ORCA’s vital marine conservation work by welcoming volunteers on board Scillonian III to collect valuable wildlife data along this 28-mile route. The records gathered over that time highlight the richness and diversity of these special waters. We are delighted to play a part in helping build a greater understanding of marine life that calls them home and to play a small part in that ongoing effort.”
The partnership has also enhanced the experience for thousands of passengers travelling to and from the Isles of Scilly, with wildlife encounters becoming one of the most talked-about aspects of the crossing.
Scillonian III master, David Redgrave, said:
“One of the most rewarding parts of sailing Scillonian III is seeing the excitement that wildlife sightings bring to everyone on board. There’s always a buzz around the ship when dolphins frequently appear alongside us, particularly when they’re bow riding with us. Passengers often gather on deck taking photos, and it’s common to see people watching in amazement as dolphins leap through the waves or seabirds diving around us as we sail. Every crossing is different, but those encounters create memories for both passengers and crew members that are unmatched.”
Moving forward
Together, ORCA and Isles of Scilly Travel look forward to continuing this important work for many years to come, helping to build an even greater understanding of the marine life that thrives around the Isles of Scilly.
