When travelling from the Kenyan coast to Nairobi after scuba diving, you are making a significant ascent. Nairobi sits at an elevation of roughly 1,795 meters (5,889 feet) above sea level. Because this altitude gain poses a serious risk of decompression sickness (the bends), you should follow the same waiting period guidelines before boarding the train as you would for flying:
- Single no-decompression dive: Wait at least 12 hours.
- Multiple dives or several days of diving: Wait at least 18 hours.
- Dives requiring decompression stops: Wait at least 24 hours.
See Divers Alert Network Guildelines
To be completely safe, many divers choose to wait a full 24 hours before making the journey up to Nairobi.
Why Altitude Matters After Scuba Diving
When you scuba dive, your body absorbs nitrogen from the compressed air you breathe. At sea level, this nitrogen safely off-gases over time. However, ascending to a high altitude—whether by plane or by taking the train up to the elevated Nairobi plateau—causes the ambient pressure around you to drop. This drop in pressure can cause the nitrogen still trapped in your body to expand into bubbles, leading to decompression sickness.
Planning Your Journey
The standard gauge railway (SGR) from Mombasa to Nairobi climbs steadily over its route, reaching nearly 6,000 feet by the time you arrive in the capital. Because this easily exceeds the 1,000-foot (300-meter) threshold where altitude changes begin to affect off-gassing, you must treat this trip exactly like a flight.
If you are planning a dive trip on the coast, consider scheduling a “down day” to explore the local beaches or historical sites at sea level before you board the train. Always check your dive computer for its specific “no-fly” or “time-to-altitude” countdown, and use that as your primary guide.
