The Merrell Hydro Moc is a water shoe well suited to summer walks where you know you're going to get wet, but want something more robust than a sandal or flip-flop. The clog-style design provides good protection from underwater hazards, but allows water to sluice through easily and is extremely easy to clean. Just bear in mind that it's particularly wide, so you may need to go down half a size.
Soft foam material
Uses some bioplastic
Supportive insole shape
Very wide fitting
Not the grippiest water shoe
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Merrell Hydro Moc with BLOOM first impressions
Most of the best water shoes we've reviewed are designed like sneakers or snug-fitting booties. The Merrell Hydro Moc is very different; a lightweight clog that feels most at home on waterfront hikes and boating trips.
The chunky design with large perforations means it's impossible not to draw the comparison with Crocs, but the Hydro Moc is lighter, softer, and more forgiving on the feet for longer walks. It also has a proper heel cup that makes it feel more like a proper shoe, plus a more supportive footbed that allows your foot to roll comfortably.
• List price: $55 / £55
• Weight: 8oz / 226g (women's UK size 9)
• Sizes: Women’s 3–9 Men’s 6-14
• Colors: Pomelo / chalk / black brindle (women's); butternut / Merrell blue / herb / chalk / maple (men's)
• Compatibility: Waterside walking, boating
There are two versions of the Hydro Moc – the standard design made from regular injection-molded EVA, and this marbled version that uses 10% algae biomass to reduce use of petroleum-based plastics. It's a small touch, but a welcome one that does a little bit to help keep waterways clear and limit use of virgin plastics.
The shoe is much lighter than it looks, and our UK size 9 review sample weighed 226g each (much less than most running shoes). The aerated foam means the shoe floats, so if you're unlucky enough to drop one, you should be able to fish it out of the water without issue.
Overall, a solid choice for summer walks and boating trips where you know your feet are going to get wet, but want something more robust than a flip-flop or sandal.
Merrell Hydro Moc with BLOOM in the field
I tested the Merrell Hydro Moc at the Gower Peninsula, Wales, and found it worked best for strolling along the sandy shore. The shoe fits fit very wide, which allows you to easily slip it on and kick it off, though if you have particularly narrow feet you may feel like you're sliding around inside. I never felt like the Hydro Moc was about to slip off my foot (the rubber heel strap keeps it in place when flipped down) but if you're usually in between sizes I'd recommend opting for the smaller of the two.
Despite this, the shoe is very comfortable thanks to its well-shaped footbed, and gives such good arch support I could imagine using the Hydro Moc as a recovery shoe for wandering about the house after a taxing run (after giving it a good wash, of course).
The perforated design means there's great ventilation despite the all-plastic construction, and means water and sand sluices through easily. It's also a piece of cake to rinse clean. Just give it a swish in the sea to get rid of any debris, then hose it off when you get home.
The molded soles provide a reasonable amount of grip, and I'd happily wear the Hydro Moc for rowing and kayaking, though I didn't feel like it had the responsiveness for stand-up paddleboarding. For that, I'd prefer something with a slimmer fit and thinner sole like the Speedo Zanpa AM.
Overall, the Hydro Moc is definitely a summer shoe, but a practical one. The closed-toe design and robust sole provide good protection from rocks and other hidden underwater hazards.
Where we tested the Merrell Hydro Moc with BLOOM
The Gower Peninsula, near Swansea, offers some of the best beaches in the UK, with miles of golden sand, scenic views, and family-friendly walking for hikers of all abilities.
Cat is the editor of Advnture, She’s been a journalist for 15 years, and was fitness and wellbeing editor on TechRadar before joining the Advnture team in 2022. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better), usually wearing at least two sports watches.