555 - 5 Days, 5 Islands Running Challenge
555 is a multi-day event across the Isles of Scilly that stages running and walking loops on five islands over five days. The main formats are a full five-day series or single-day entries, with each distance run on clearly marked island loops.
Distances offered:
- 5 Marathons total 211 km / 131 miles
- 5 Half Marathons total 106 km / 76 miles
- 5 Island Loops approx. total 55 km / 35 miles
Daily course details list loop lengths by island: St Martin’s (10 km per loop), Tresco (10 km per loop), St Agnes (9 km per loop), Bryher (8 km per loop), and St Mary’s (17 km per loop). The published itinerary covers registration on 3 October and island stages from 4 to 8 October 2026.
Time limits are set for each distance. Marathon participants have a finish limit equivalent to about 9:15 min/km. Half marathon and single loop entrants have minimum finishing windows and walking pace guidelines appropriate for slower participants and families.
Each island provides an indoor event hub with toilets, hot and cold water, and shelter. Participants may leave a kit bag with personal food and fuel at the start point for access between loops. For convenience across the week, staying on St Mary’s is recommended. Visit the organization's website for the most recent information.
Itinerary
- Sat 3rd. Registration.
- Sun 4th. St Martin’s (10k per loop)
- Mon 5th. Tresco (10k per loop)
- Tue 6th. St Agnes (9k per loop)
- Wed 7th. Bryher (8k per loop)
- Thur 8th. St Mary’s (17k per loop)
Your 555! Options
- 5 Marathons • 5 Islands • 5 Days. Total: 211 km / 131 miles
- 5 Half Marathons • 5 Islands • 5 Days. Total: 106 km / 76 miles
- 5 Island Loops • 5 Islands • 5 Days. Approx. Total: 55 km / 35 miles
Each distance uses a set number of clearly marked island loops.
Daily Time Limits
- Marathons: 6 hours 30 minutes, equivalent to 9:15 min/km or 14:45 min/mile
- Half Marathons & Single Loops: At least 5 hours 30 minutes to finish
- Half marathons: 15 min/km or 25 min/mile
- Loopers: 2.5 km/hr or 1.5 mph (perfect for walkers and families)
Event Hub & Support
- A dry indoor venue on each island provides the start/finish area
- Access to toilets, hot and cold water, and shelter
- Runners may leave a kit bag with personal food and fuel at the start point to access between loops
For the most convenient experience throughout the week, we strongly recommend staying on St Mary’s. Adventure awaits.