The temperature at the water's surface is about 78º F -- a hot day back home for most of my students. When it is time to don their wetsuits, my students sometimes groan and complain about squeezing into the tight neoprene. Many of my beginning divers even refuse to use a wetsuit! With rare exceptions, these divers come up shivering. Before heading to a tropical dive paradise for your summer vacation, consider the following reasons that you may need a wetsuit even in warm water.
• Submerging yourself in water lower than your body temperature will eventually make you cold. Remember your Open Water Course? You learned that water wicks heat away from your body up to 25 times faster than air -- even warm water! I see divers emerge shivering from dives in 80º F water daily.
• Diving is different from other water sports because your head is completely submerged in the water. A huge percentage of your body's blood flows to your head, which makes it responsible for a significant portion of your body's heat loss. This is the reason surfers can stay in chilly water for hours, but a diver in the same water will quickly become cold.
• The longer you spend underwater, the colder you will be. Even if you can do 20 minute dives in your short suit at the cool quarry back home, it may still be a good idea to use a wetsuit in a tropical location. Shallow, easy reefs can make for long dives that slowly but steadily drain the heat from your body.
• Are you tough and strong? Do you think you won't get cold because you handle every other physical challenge well? Remember that the less body fat a person has, the more quickly he will chill underwater. I have observed that the biggest demographic of shivering divers are "tough" young guys who don't think they need a sissy wetsuit.
• The more dives you do, the colder you will become. Keep this in mind when choosing a wetsuit for a dive holiday. If you are diving every day, you will become more chilled on each successive day. Divers planning on diving multiple days may need a longer or thicker suit than they would need for a single day of diving.
• At many dive sites there is a thermocline (where the water suddenly cools at a certain depth). Warm surface water may not be a good indication of the water temperature that you will experience on a dive. Ask your guide if there is a thermocline before choosing your level of exposure protection.
Don't be fooled! "Warm" water can end up feeling very cold by the end of a dive. Think of this the next time you see a photo of a diver wearing only a swimsuit. Ask yourself, "Was that skinny, bikini-clad model really comfortable, or were the goosebumps just airbrushed out?"
Speak Up! What kind of wetsuit do you use for diving in a tropical environment?
Image copyright istockphoto.com, strmko
Comments
I have been thinking about this all week. I am heading to Mexico next week and it is hard for me to think that I will be taking a 5mm and a hood in the middle of summer. We have upper 80s in our local lake at home so we have been in shorts for about a month. But I know that I will be looking for a thicker suit if I don’t take my 5mm after a few days in the cenotes.
Mike,
My personal config in the cenotes is always a 3mm full suit and for sure a beanie — but I have a couple of extra LBs. If you get cold easily, then a 5mm suit would still be very comfortable. Water temp about 76 degrees at all levels, but after an hour, it can get chilly!
George
I haven’t really tried diving but I want to soon! It’s one of my dreams now.. Is the water really relatively warmer when diving in a suit than just swimming?
2QHI7u In awe of that answer! Really cool!
I live in Minnesota and come with a little extra insulation, well-suited for swimming in Minnesota lakes. On a recent trip to Barbados. the surface water temperature was 84 with a thermocline to 81. I wore a shorty. The skinny dive masters wore full wet suits. I run through my air about 4 times faster than they do, but twice I saw dive masters end the dives clearly on the edge of (or perhaps even well into) hypothermia.
The moral of the story? Know your personal limits and don’t assume they’ll be the same as someone else’s. Even the newbie diver may be more capable in a particular situation than the guy with hundreds of dives.