What Are Dry Suits?
Unlike wetsuits that let water in and trap it against your skin, dry suits are completely sealed environments. They keep you dry by creating a waterproof barrier between you and the ocean — allowing you to dive in water as cold as 28°F (-2°C) while staying toasty warm.
The secret is in the construction: waterproof neoprene or crushed nylon shells with latex or silicone seals at the neck and wrists, and integrated boots or ankle seals. A waterproof zipper (usually across the shoulders or diagonally across the chest) creates the entry point.
How Do They Work?
Dry suits work on a simple principle: they trap air. You wear insulating undergarments beneath the suit, and the air layer between your body and the suit material provides insulation. As you descend, you add air to the suit through an inflator valve (similar to your BCD) to maintain this insulating layer and prevent "squeeze."
On ascent, you release air through an exhaust valve, typically mounted on your left shoulder. Managing this air is crucial — too much and you'll float uncontrollably; too little and you'll feel the crushing pressure of deep water.
Types of Dry Suits
Neoprene Dry Suits: Made from compressed neoprene (3-7mm), these offer excellent insulation even without undergarments. They're durable, buoyant, and provide some thermal protection even if flooded. Popular brands include DUI and Bare.
Membrane/Trilaminate Suits: Thin, lightweight shells made of layered materials (nylon butyl rubber). They offer no insulation on their own — you rely entirely on undergarments. But they're lighter, pack smaller, and dry faster. Think of them as underwater windbreakers.
Why Dive Dry?
Simply put: comfort and safety. When water temperatures drop below 60°F (15°C), wetsuits become inadequate for long dives. Dry suits allow you to:
• Explore shipwrecks in the Great Lakes (40-50°F year-round)
• Photograph kelp forests in California's Channel Islands
• Dive ice-covered quarries and lakes
• Extend your season into late fall and early spring
Getting Certified
Dry suit diving requires specialized training. Most certification agencies (PADI, SSI, NAUI) offer a Dry Suit Diver specialty course, typically consisting of:
• 1 classroom session on suit types, maintenance, and safety
• 1 confined water session (pool) to practice buoyancy
• 2 open water dives in controlled conditions
The course teaches critical skills: managing suit inflation, emergency procedures (like a flooded suit), and proper weighting (dry suits require significantly more weight than wetsuits).
🤿 Fun Fact
The first commercially successful dry suit was invented in 1911 by Italian diving pioneer Alberto Gianni. It used rubberized canvas and metal clamps for seals. Modern silicone seals weren't widely adopted until the 1980s!
Pro Tips
Maintenance matters: Rinse your suit thoroughly after salt water dives, and apply silicone grease to zipper teeth monthly. Store it hanging, never folded.
Layer smart: Merino wool base layers work better than cotton (which traps moisture). Avoid bulky fleece that compresses at depth and loses insulation.
Practice buoyancy: Dry suit diving requires different technique. Most divers over-weight themselves initially. Start with 2-4 lbs less than you think you need.