We all know that one diver. They hit the water in Cozumel or San Carlos, the water is a balmy 80 degrees, and by minute 35, their teeth are chattering around their regulator mouthpiece. If that diver is you, you know how miserable it is. Being cold doesn’t just ruin the fun of a dive; it spikes your air consumption, ruins your buoyancy because you are shivering, and leaves you utterly exhausted on the boat ride back.

Most divers try to solve this problem by buying thicker and thicker wetsuits. But moving from a 3mm to a 5mm, or a 5mm to a full 7mm suit adds a massive amount of bulk, restricts your movement, and requires you to pile on a ton of heavy lead weights.

Before you completely change your wetsuit, you need to look at the one part of your body you are leaving totally exposed to the ocean: your head.

The Science of the “Brain Drain”

Your head is basically a giant radiator. It requires a massive amount of blood flow to keep your brain functioning, and the blood vessels in your head are very close to the surface of your skin. Unlike your arms and legs, the blood vessels in your head don’t constrict when you get cold.

When you submerge your bare head in water (even warm, 80-degree tropical water), that constant blood flow acts like a conveyor belt, pulling the heat directly out of your core and radiating it into the ocean. You can wear a thick 7mm wetsuit, but if your head is bare, your body is constantly fighting a losing battle to stay warm.

“But I Hate How Hoods Feel!”

Whenever I tell a student they need a hood, I usually get the same pushback: “They feel claustrophobic,” “They choke me,” or “I can’t clear my ears when I wear one.”

If you hate scuba hoods, it is almost certainly because you rented an old, stiff, poorly fitted one ten years ago. Modern scuba hoods, like the K01 Classic Hood, are a completely different ballgame. They are made from ultra-stretchy, buttery-soft neoprene that contours perfectly to your jawline without pressing on your windpipe.

The Ultimate Cheat Code: The Hooded Vest

If you want maximum warmth with minimal bulk, the absolute best investment you can make is a hooded vest.

Instead of just a standalone hood that tucks into your wetsuit collar, a hooded vest is a single, seamless piece of 2mm or 3mm neoprene that you wear underneath your standard wetsuit. It traps your core heat, completely seals your neck, and keeps your head toasty warm. It is the ultimate modular system: wear your 5mm suit bareheaded on the warm days, and slide the hooded vest underneath it when you hit the chilly Lake Pleasant thermoclines.

Get Fitted and Get Warm

Just like a wetsuit, a hood only works if it fits perfectly. If it is too loose, cold water will constantly flush through your ears. If it is too tight, it can actually press against your carotid artery and make you feel dizzy.

Stop shivering through your bottom time and start enjoying the reef. Come visit us at 72 Aquatics, and let us fit you with a high-stretch hood or hooded vest. It is the smallest piece of gear that will make the biggest difference in your diving!