Key takeaways
- Box jellyfish and Irukandji are a seasonal risk in tropical Queensland waters, roughly November to May, and the lycra suit on this trip is provided for exactly that.
- Reef sharks live on the Great Barrier Reef and may be seen on a drift snorkel here. They are not a threat to snorkellers.
- The drift snorkel moves with the current rather than against it, and flotation devices are provided if you want to rest without leaving the water.
- Cairns sun burns fast, and the seventy-five minute catamaran crossing each way is enough to bring on seasickness if you are prone to it, so plan for both before boarding.
What a guided drift snorkel actually involves
Both dive and snorkel sites, the Wonder Wall and the Aquarium, lie along the seaward margin of Upolu Reef, with the sand cay sitting on the same reef system. This trip is built around two guided water sessions, with lunch on board between them. A drift snorkel means the group moves with the current along the reef rather than swimming laps back and forth, with a guide leading the way.
At the Wonder Wall the coral comes to within about a metre of the surface, close enough to look at without diving down for it. Coral is a living structure. Touching it, standing on it or brushing it with a fin damages the coral and can cut the skin doing it, which is worth knowing on a site where it sits this close to the surface.
A glass bottom boat tour is included as well, run separately from the drift snorkel, so seeing the reef does not have to mean getting in the water at all on the days you would rather stay dry.
Marine stingers and the lycra suit
Marine stingers, including box jellyfish and Irukandji, are a genuine seasonal hazard in tropical Queensland waters, roughly November to May. This is what the lycra suit provided on this trip is for: a full body layer that keeps stinging tentacles off the skin without you needing to track the calendar yourself.
Wetsuits are also provided on a seasonal basis alongside the lycra suits. Neither is optional dress-up. Wearing the suit given to you on the day does the job it is designed for, whatever the water happens to look like when you get in.
A marine guide leads the drift at Upolu Reef, close enough to the Wonder Wall's coral to see without diving.
Reef sharks: what you might see
Reef sharks live on the Great Barrier Reef, and a group doing a drift snorkel over Upolu Reef may see one over the course of a day. Reef sharks are not a threat to snorkellers, and a sighting at a distance is an ordinary part of a day on the reef, not a reason for alarm.
What turns up on any one drift is not something to promise in either direction. Wearing the flotation device provided and following the guide's line across the reef is the same drift whether or not a shark passes underneath it that day.
Getting tired in open water
Tiredness, not stingers and not sharks, is the problem most snorkellers actually run into on a trip like this. This trip is run as a drift, not a there-and-back swim: the group moves with the current along the reef instead of swimming against it, with a guide leading the way. Moving with the current asks less of your arms and legs than swimming laps does.
Flotation devices are provided and are worth using without any embarrassment. Holding one under an arm for a rest takes no effort and is exactly what it is there for. The glass bottom boat tour, run separately from the drift snorkel, is another way to spend part of the day at the reef without being in the water for both full sessions.
75 min
That is the one way catamaran crossing to Upolu Reef, the length of open water most likely to bring on seasickness if you are prone to it.
Guides in the water with the group
Marine guides are part of this trip, not an add on: the drift snorkel is guided, and snorkelling with a marine naturalist is part of what is included. That is a different arrangement from an unsupervised swim off a beach, where nobody is in the water with you but the people you came with.
What that does and does not cover is worth being clear about. A marine guide leading a drift snorkel is there to lead the drift and point out what is on the reef, and having one in the water changes the day from a swim on your own to a swim with somebody who knows the site. It is not a lifeguard tower with a whistle, and watching your own limits in open water stays yours to do.
Sun at this latitude
Cairns sits in the tropics, and the sun here burns faster than it does at home for most visitors, including on a day that starts cloudy or is spent mostly in the water. Water reflects UV back onto the skin more than most people expect, so a morning snorkel session is not a reason to skip sunscreen before boarding.
Reapply sunscreen through the day rather than trusting one application at breakfast to last eight and a half hours. The lycra suit doubles as sun cover for the torso and arms during the water sessions, and a hat and sunglasses do the rest of the work on deck between them. Sunscreen, sunglasses and beachwear are worth packing before boarding, not after the first sting of sunburn shows up.
The crossing and seasickness
Getting to Upolu Reef takes about seventy-five minutes each way by catamaran, and the return trip is the same again at the end of the day. A fast catamaran covering that stretch of open water is exactly the kind of crossing that brings on seasickness in people who do not usually get seasick on smaller boats or shorter trips.
None of the useful advice here is exotic. Eat something plain before boarding rather than nothing at all, keep to the open deck where you can see the horizon rather than staying below, and avoid reading or looking at a phone screen while the boat is moving. If you know from experience that you are prone to motion sickness, plan for it before the day rather than during the crossing.
