Fins and masks are where diving begins. No matter how advanced the rest of your configuration is, poor visibility or inefficient propulsion will compromise the entire dive. In technical diving, where precision, endurance, and reliability matter more than anywhere else, these two pieces of gear deserve the same careful attention as your regulators or your wing.
Why Fins and Masks Matter in Technical Diving
Recreational divers can get away with average fins and a mask that mostly fits. Technical divers cannot. A mask that leaks at depth wastes gas on clearing and creates a distraction when focus should be elsewhere. Fins that lack power or control make it impossible to execute precise kicks — frog kicks, back kicks, helicopter turns — that are essential in overhead environments and around delicate wreck structures.
The right combination of fins and mask becomes an extension of the diver’s body. You stop thinking about your equipment and start thinking about the dive. That is the goal.
Fins and Masks Categories
Fins
Open-heel blade fins built for technical diving. Stiff enough to deliver power in current and with heavy gear, responsive enough for precise propulsion techniques including frog kick, flutter kick, and back kick.
Masks
Low-volume masks designed for technical and professional diving. A close fit to the face reduces internal air space, making clearing easier and improving the diver’s downward field of view.
Accessories
Mask straps, fin straps, spring straps, anti-fog solutions, and other items that complement and maintain your fins and mask setup.
Fins in Technical Diving
Technical diving demands open-heel blade fins — also known as paddle fins. Unlike split fins, which are designed for efficient flutter kicking in relaxed conditions, blade fins provide the power and control needed for a full range of propulsion techniques. Frog kick, modified frog kick, back kick, helicopter turn — all of these require a stiff, responsive blade that gives the diver direct feedback with every stroke.
Open-heel fins are worn with drysuit boots or neoprene booties, which means the same fin works across different exposure protection setups. The foot pocket should grip the boot firmly without crushing the toes. A loose fit wastes energy; a tight fit causes cramps. Many technical divers replace the standard rubber straps with spring straps for faster donning and doffing and a more consistent fit.
Blade stiffness matters. A fin that is too soft flexes too much and loses power — especially when carrying extra equipment like stage bottles or a scooter. A fin that is too stiff demands more leg effort and can cause fatigue on longer dives. The right stiffness depends on the diver’s leg strength, kicking style, and typical diving conditions.
Masks in Technical Diving
The defining feature of a technical diving mask is low internal volume. A low-volume mask sits closer to the face, which means less air is needed to equalise it during descent and less effort is required to clear it if water enters. In technical diving, where gas management is critical, this adds up over the course of a dive.
A close-fitting, low-volume mask also provides a wider downward field of view, which matters when reading gauges, checking clip placements, or monitoring equipment mounted on the chest. The skirt should seal evenly around the face without pressure points — even small leaks become a persistent annoyance on a 90-minute decompression dive.
Frameless masks are a popular choice in technical diving. They fold flat for storage, sit very close to the face, and are easy to fit into a backup mask pocket. A backup mask is standard practice in tech diving — if your primary mask fails during an overhead dive, you need a replacement immediately accessible.
What to Look for in Fins and Masks
- Fin type — open-heel blade fins are the standard for technical diving. They support all kick styles, handle heavy gear loads, and work with both drysuit boots and neoprene booties. Split fins lack the stiffness and control required for precise manoeuvring.
- Blade stiffness — match the stiffness to your leg strength and diving style. Stiffer fins deliver more power but require more effort. A fin that exhausts you on a 60-minute dive is not the right fin.
- Mask volume — lower is better for technical diving. Less air to equalise, less gas wasted on clearing, better field of view. Try the mask on your face without the strap — it should stay in place with a gentle inhale through the nose.
- Mask skirt fit — the silicone skirt must seal evenly around your face. Gaps at the nose bridge, temples, or upper lip are common fit issues. A mask that leaks on the surface will leak underwater.
- Strap system — spring straps on fins eliminate the need for adjustment and make donning faster. On masks, a wide split strap distributes pressure evenly and stays in place better than narrow straps.
Maintenance and Care
After every dive, rinse both fins and mask with fresh water. For masks, avoid touching the inside of the lens — oils from fingers promote fogging. Store masks in a protective case or box to prevent the silicone skirt from deforming. Never leave a mask face-down on a hard surface in direct sunlight — UV degrades silicone over time and heat can warp the lens.
Fin straps — especially rubber ones — lose elasticity with age and UV exposure. Inspect them regularly and carry spares. Spring straps are more durable but should still be checked for corrosion at the attachment points. Fin blades can develop stress cracks near the foot pocket after extended use — inspect this area periodically.
Before a new mask’s first use, treat the lens to remove the factory film that causes persistent fogging. A mild abrasive like non-gel toothpaste or a dedicated lens prep solution, rubbed gently on the inside of the lens and rinsed, removes this film. Most fogging issues with new masks trace back to skipping this step.
Frequently Asked Questions
Why do technical divers use blade fins instead of split fins?
Blade fins — also called paddle fins — provide the power and control needed for a full range of kick techniques used in technical diving: frog kick, back kick, helicopter turn, and modified flutter kick. Split fins are optimised for a narrow, rapid flutter kick and lack the stiffness to perform these precision manoeuvres effectively. When carrying heavy equipment or diving in current, blade fins deliver significantly more thrust.
What makes a mask suitable for technical diving?
Low internal volume is the most important feature. A low-volume mask requires less air to equalise and clear, sits close to the face for a better field of view, and folds flat for use as a backup mask. The skirt must seal reliably — even a minor leak becomes a problem on dives lasting over an hour.
Why does my new mask keep fogging?
New masks have a factory-applied film on the inside of the lens from the manufacturing process. This film causes persistent fogging that standard anti-fog solutions cannot fully prevent. Remove it before the first use by gently scrubbing the inside of the lens with non-gel toothpaste or a dedicated lens prep solution, then rinse thoroughly.
Are spring straps worth it for fins?
For most technical divers, yes. Spring straps eliminate the need for manual adjustment, provide a consistent fit every time, and make donning and doffing fins faster — especially in drysuits or heavy gloves. They are more durable than rubber straps and less prone to loosening during a dive.
Should I carry a backup mask?
In technical diving, a backup mask is standard practice — especially in overhead environments where surfacing is not an option. A frameless low-volume mask folds flat and fits easily into a pocket on your harness or exposure suit. Losing your only mask during a cave or wreck penetration is a situation you do not want to face without a spare.