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Scuba diving is a thrilling recreation that comes with a lot of risks. Whether a newbie to the sport or an experienced diver, getting the right equipment is the way to go.
That said, one of the things you need to invest in is a wetsuit with adequate thickness. This essential item protects you from cuts and stings but, more importantly, provides warmth underwater.
Recognizing the importance of this matter, we prepared this wetsuit thickness guide scuba divers will want to look into!
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Why Is Wetsuit Thickness Important?
There are two main reasons you need to wear a wetsuit—comfort and safety. For starters, it protects against jellyfish stings and possible abrasions from rocks or other sharp objects.
On top of that, it enables you to stay warm underwater so you can move and enjoy scuba diving activities.
How is this possible?
Synthetic rubber, neoprene, is a popular material used in most wetsuits. Due to its water resistance properties, a common misconception is that wetsuits are waterproof.
However, that’s not entirely true. The zippers or seams will need to allow water entry to a certain degree for your wetsuit to be effective.
When that happens, a layer of water forms and warms up as it comes in contact with the body. That amount remains trapped within the clothing, due to the microbubbles in its structure.
As a result, you now have a barrier between the external cold water and your body. This slows down heat loss to keep you warm.
Nevertheless, you need a wetsuit with the correct thickness for optimal results.
What If My Wetsuit Is Too Thin?
A wetsuit that’s too thin will make you lose heat faster. It won’t be long before you feel uncomfortable. That can take away the fun from your adventure or cut it short altogether.
Yet, it can be worse. If you feel too cold and stay underwater for extended periods, you may be at risk of hypothermia. This condition occurs when your body temperature goes below normal.
Even the slightest shiver should get you out of the water immediately. That’s a tell-tale sign you shouldn’t ignore.
Otherwise, it can lead to life-threatening consequences, such as organ failure or death.
What If My Wetsuit Is Too Thick?
Naturally, the thicker the wetsuit, the more it retains body heat. Therefore, you feel warmer for quite some time.
Still, it doesn’t mean that the thickest suit is the best for every dive.
The trade-off lies between flexibility and warmth. A thin wetsuit allows easier movement in the water but you may feel cold instantly.
On the other hand, a thick wetsuit is less stretchy and more buoyant. It’ll be harder to move in it once underwater. You’ll tire out much faster too.
Factors to Consider in Choosing the Wetsuit Thickness
Now, we have a better understanding of the importance of a correct wetsuit thickness.
Let’s dive further into the factors you need to consider in your selection.
1. Water Temperature
Will you be diving in the tropics with temperate waters? Or are you planning a trip to a cold water dive spot?
Before you go scuba diving, do a quick search about the water temperature in the area. Since you’ll be submerged in water most of the time, that’s your main consideration for your wetsuit’s thickness.
Additionally, don’t assume that hot weather means warm waters. It’s not always the case, especially when the location has just transitioned from a colder weather.
Simply put, the ocean warms and cools down slower than land. So, keep that in mind.
Anyway, by now, you know that colder water requires a thicker suit. Conversely, warmer water matches a thinner suit.
2. Type of Activity
The type of activity is another consideration for your suit. How long will you be staying underwater? Will you be moving around a lot? At what depth will you be staying?
You should be able to answer these questions before you make that wetsuit purchase.
That said, remember that the layer of water that’s keeping your body warm may eventually turn cold. Although how cold will depend on the time you spend in the water.
So, if you plan to stay longer, get a suit with extra thickness early on.
However, if you’ll be moving constantly, wearing a thinner suit is recommended. That’s because more heat will be generated by the body. Plus, you’ll have more flexibility underwater.
Furthermore, consider the depth you’re going into. Remember, as you go deeper, the water temperature lowers. So, once more, you need a thicker suit.
Another thing to note is that the microbubbles in the neoprene material undergo compression as you dive deeper. The reason for that is the increased pressure that pushes the gas molecules together. As a result, your suit will feel thinner.
Don’t worry, though, it’ll return to its natural state once you go back up to the surface.
3. Sensitivity Levels
Your sensitivity level is another thing of utmost consideration. People react to temperatures differently. What may be bearable for some, may feel too cold for you.
If that’s the case, choose a wetsuit that has a slightly higher thickness than suggested. Other scenarios will also require additional accessories such as boots, hoods, and gloves.
These items will add weight and can be annoying if you’re not used to them. Yet, they can be greatly helpful in cold dives. That’s especially true since significant heat can escape through the head.
4. External Factors
Lastly, you need to take into account external factors, such as air temperature and wind speed in choosing your wetsuit.
On windy days and cooler surrounding air, more body heat is lost to the environment.
Are you scuba diving in such conditions? If you are and will be going in and out of the water often, you may want to wear a thicker wetsuit to keep you warm.
How to Interpret Wetsuit Thickness Values
If you’ve been looking for wetsuits online, you may have noticed two numbers like “3/2” on some product descriptions. These values indicate the thickness of the suit.
The first number refers to the thickness of the torso area, which is 3 mm. On the other hand, the second pertains to the legs and arms, which are 2 mm.
In some cases, you may see three numbers. Take, for example, 6/5/4. You can interpret it as 6 mm thick on the core, 5 mm on the legs, and 4 mm on the arms.
You may ask, why aren’t measurements uniform throughout the suit?
Here’s the deal. Wetsuits are thicker on the torso since most of your body heat is generated in that area.
Since the core gives a higher temperature gradient with the surrounding water, it’s also more prone to heat loss. Hence, it requires more protection.
As for the legs and arms, the thinner material enables you to move around easily.
Wetsuit Thickness for Various Water Temperatures
As we said, wetsuit thickness is guided by several factors but mainly water temperature and your sensitivity towards the cold.
For instance, at water temperatures above 82°F (28°C), you can go scuba diving without the need for a wetsuit. You can simply wear a rash guard or a bathing suit to dress the part.
However, once temperatures drop below that, consider wearing a wetsuit for your scuba diving sessions.
In warmer weather, you can also grab the opportunity to ditch the full suit and don a spring suit or shorty, instead. With shorter legs and long sleeves out of the way, you get more freedom underwater.
Nonetheless, if you love the challenge of diving in chilly waters below 63°F (17°C), you’ll need better clothing than your typical wetsuit.
A semi-dry or dry suit are smarter options that’ll give you more warmth and comfort. The difference lies in the construction.
With a semi-dry suit, you get thicker neoprene, with neck, wrist, and ankle seals that are made to fit more snuggly.
On the other hand, a dry suit acts in the total opposite manner as a wet suit. It works by waterproofing your entire body. That’s made possible by sealing all water entry points and using waterproof zippers.
So with these things in mind, here’s a quick guide you can use for your wetsuit purchase:
| Water Temperature | Wetsuit Thickness | Wetsuit Type |
| Above 82°F(28°C) | Not applicable | A regular rash guard or bathing suit will do |
| 77–82°F (25–28°C) | 2 mm or 1 mm | Spring suit or full-length suit |
| 72–77°F (22–25°C) | 3 mm | Full-length suit |
| 63–72°F (17–21°C) | 5 mm | Full-length suit or semi-dry suit |
| 50–63°F (10–17°C) | 7 mm or 8/7 mm | Full-length suit or semi-dry suit |
| 41-50°F (5–10°C) | 8/7 mm | Semi-dry suit or dry suit |
Key Takeaways
Scuba diving, like any other adventure, comes with its dangers. To minimize the risks, you should invest in the right gear, starting with a wetsuit.
In this regard, we prepared this wetsuit thickness guide, which scuba divers can reference for their wetsuit purchases.
However, keep in mind that this table is quite general. If you’re more sensitive to the cold than others, you can go for the next thickness category in our recommendation.
