The Importance of Proper Hydration in Scuba Diving

We think of running, cycling, and working out as physical activities where hydration is absolutely critical. But scuba diving does not seem to have that same critical need, so hydration tends to be downplayed by scuba divers, reduced to just a “good practice” when going diving. Think again! In this blog we will explore why proper hydration is so vital to healthy scuba diving.

It’s no secret that our bodies depend on water for survival. In fact, water makes up over half of our body weight. Every cell, tissue and organ in your body depends on water for proper functioning. Water is essential for joint lubrication, cardio-vascular efficiency, regulating temperature, and removing bodily waste.

HOW DO WE LOSE WATER WHEN SCUBA DIVING?

“Dehydration,” by definition, simply means a lack of balance in the body’s fluids. Specifically, it refers to a negative balance, or too few fluids, as opposed to having a fluid surplus. The balance of fluid is maintained by a complex process of hormones and electrolytes, and it doesn’t take much to throw it off. You might be surprised by how many elements of diving play a part:

Respiration

Our bodies naturally loose water through exhalation. You can notice this just exhaling on a glass and seeing your exhaled water vapor create a fog on that glass. But when scuba diving, water loss through respiration is increased significantly due to our breathing of filtered and very dry compressed air. This air with virtually no humidity draws even more water out of the body during respiration.

Immersion Diuresis (A technical term for “weeing in our wetsuits”!)

As we dive, ambient water pressure and the cooler temperature of water may both have a role in shunting blood from the extremities (arms and legs) into the thorax. When the body recognizes the increase of blood around core organs, and the subsequent increase in blood pressure, it attempts to flush fluids by increasing urine output. That is the reason for the frequent need to urinate during dives.

Vomiting

If you’ve spent time on a dive boat, you understand the plight of those who are plagued with sea sickness. Not only is it embarrassing and uncomfortable, but vomiting can leave the body in a severely dehydrated state along with a severe electrolyte imbalance. The more someone vomits, the greater the chance of severe dehydration.

Alcohol

Dive trips are often fun, tropical holidays and it is important to recognize that drinking alcohol is quite common during dive trip holidays. Alcohol consumption actually counters water consumption since it is a diuretic. Alcohol contains high levels of sugar, levels higher than are normally found in the body. When those higher levels are present, the blood and other fluids have to work harder to move around and dilute them. Alcohol also serves as a trigger for the antidiuretic hormone; when alcohol in any form is present in the body, the hormone is turned off and the increased urine output begins.

Caffeine

The same can be said for caffeinated and high-sugar drinks, as they too turn off the antidiuretic hormone. So if you’re trying to hydrate with fizzy drinks, coffee, high-energy drinks or beer, you are actually not making the best choice, as these are not optimal fluid sources.

Sun

Our best dive locations have excellent sunlight. As we engage in this outdoor activity we are susceptible to large amounts of sun exposure. A mild to moderate sunburn leaves the skin red, hot and painful. Just as with any other skin burn, the body rushes fluid to the skin. Being outdoors, air will evaporate the moisture on the skin, leading to further fluid loss.

Sweating

That sweating contributes to dehydration is no surprise. But people don’t often realize how much they’re actually sweating inside their wetsuits. Even if you’re not roasting, if you’re sweating at all outside the suit, you’re sweating all over underneath it. Why? Because the suit doesn’t allow for the body to cool by air evaporation, so it just keeps trying and trying. The longer you have that suit on out of the water, the more water and electrolytes you’re losing due to sweat and you may not even realize it. Try to keep the suit off until right before you’re getting ready to dive.

Wind

Because scuba diving is an outdoor activity, another natural factor contributing to dehydration is wind. Not only do the tropics have healthy breezes, but a swift speedboat ride to a dive site can remove surface moisture and sweat from exposed skin. The faster the wind, the higher the rate of evaporation.

HOW TO TELL IF YOU’RE DEHYDRATED…

Now we’ve gone over the various ways divers get dehydrated, so how do you know if you are dehydrated? Some symptoms are very obvious, others maybe not so much.

Thirst
Headache
Dark urine (ideally urine should be nearly clear)
Sleepiness
Lightheadedness
Dizziness
Confusion

HOW TO STAY HYDRATED…

Well firstly, what you do NOT do is drink gallons of water before or during your diving holiday. Too much water can have just as many hazards as too little. The key is just to remain habitually hydrated by drinking normal amounts of water at regular intervals prior to and during your holiday. And yes, water is your best choice. Some sports drinks are good too, but remember they do have high sugar content which can counter some of the hydration you get. The bonus with sports drinks is that they help with replenishing electrolytes. But don’t drink them in place of water, drink them in addition to water. Energy drinks contain a lot of sugar and caffeine, both of which are going to act against your hydration efforts, so best to stay away from them. Water, water, water.

Eating helps with hydration too. We offer fruit after and in-between dives, eat it because it contains water, vitamins and fructose. Some salty snacks will replenish electrolytes too.

Basically, if you do anything that causes fluid loss then you need to replace those fluids. If you get sunburned, you need to drink more water. If you’re drinking a lot of alcohol, you need to drink more water. If you’re vomiting, you need to drink more water. Get the idea?

Hopefully now you understand the reason that divers need to stay hydrated, how fluid loss occurs for divers, and how to fix it. We all want to have safe and healthy dive trips and holidays and proper hydration is part of that. Incorporate it into your next dive plan!