When going swimming in the sea, is it better (scientifically, emotionally or spiritually) to enter quickly or to take your time?
Stephen Johnson
Eugene, Oregon, US
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I have done thousands of open-water swims and hundreds of open-water races.
When planning to swim in the ocean, the most important aspect to consider isn鈥檛 science, emotions or spirituality, but safety. First, be sure there are no hazards, such as coral, rocks or boats. Second, is the ocean calm, are there breaking waves and how is water entering and exiting the beach? If there are breaking waves, it is imperative to watch carefully and enter quickly during a break between the wave sets. It is also important to swim quickly beyond the surf impact zone.
In these conditions, good swimmers look for a place where the water exits the beach (a rip current) and use it to help get them out. In calm conditions, these precautions are unnecessary, but swimmers should still look for the signs of current and have a plan on where they intend to swim. There is nothing like in the ocean, but it isn鈥檛 a swimming pool.
David Bortin
Whittier, California, US
Insofar as science is the acquisition of information about our surroundings (and technology is the use of that information to improve our lives), I suppose it could be argued that it is 鈥渂etter鈥�, scientifically and technologically, to dip a toe into the water first, to help decide whether to commit to going all in.
But if you need to abandon a sinking ship before it drags you under, it might be better, emotionally or spiritually, to make haste. So subjective betterment really all depends on your circumstances, values and priorities.
Mark Thompson
Tewkesbury, Gloucestershire, UK
When entering the sea, especially if it is cold, the best approach can vary depending on personal preference and comfort. However, the advice from cold-water swimming clubs is to enter slowly.
When you immerse yourself in cold water, your body experiences a cold shock response. This is characterised by a sudden gasp, followed by rapid breathing and increased heart rate and blood pressure.
This reaction happens when you get into water at about 10 or 15掳C (50 or 59掳F), but it can also occur at higher temperatures, between 20 and 25掳C (68 or 77掳F), although not to such extremes. The body鈥檚 involuntary response can become especially problematic if your airways are underwater when you need to breathe, or if you have an underlying heart or vascular condition.
This shock is produced by the stimulation of cold thermoreceptors on the skin鈥檚 surface, and it is especially likely to happen if the body hasn鈥檛 been acclimatised to the water temperature by entering slowly. In such cases, swimmers experience a chilling sensation on their skin. However, if the water temperature is below about 8掳C (46掳F), pain receptors will also be stimulated.
Fortunately, none of this happens when you enter your nice warm bath at home, which is my preferred method of entering water.
Kathy McClellan
Sydney, Australia
It is much better to enter quickly. You are there to swim. Otherwise, just paddle in the shallows.
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