There are several key barriers that inhibit a lifeguard from effectively seeing objects in the aquatic environment, which can create areas of what is sometimes referred to as 'dead water'. Drowning can occur in these areas without being noticed, even if the area is near a lifeguard.
Below are some of the key factors to keep in mind.
Glare
This is one of the most prevalent problems when scanning an aquatic environment. Facility lights or the sun shining on the pool cause light to reflect off the water making it impossible to see what is below the reflective area, even if a person is just centimetres below the surface. The only way to prevent this is to move your supervising position until the glare is gone. Be aware that the best position during the day will be different at night as the glare will change.
Glare can also cause overstimulation of a lifeguard’s eyes, which can result in temporary blindness, confusion and sometimes pain. Lifeguards should wear good quality polarised sunglasses and a comfortable hat whenever the sun is strong enough to cause eye strain. These will cut down the total amount of light reaching their eyes but still permit good vision.
Shade
While too much light can prevent you seeing under the water, a lack of light can also obstruct effective supervision. Shaded areas over the water can form black or dark spots in the water and can stop you from seeing patrons on or under the water’s surface. As with situations involving too much glare, move your supervising position around to prevent shaded areas creating dead water areas.
Low or poor light
Recognition of objects in daylight involves more factors than we realise. Details of shape, form, colour and general appearance all play a part. In a low-light situation many of the visual ‘clues’ are missing, and the appearance can seem unfamiliar. White objects stand out more prominently, whereas greys, browns and greens become indistinguishable. It is therefore essential that a lifeguard be fully familiar with what an object looks like under varying light conditions.
Disturbance of the water surface
Disturbance on the water surface distorts the image of an object under the water making it very difficult to recognise. Lifeguards may see a distorted shadow on the bottom that doesn’t look like a body or could be mistaken for a towel or a t-shirt. Disturbance may be caused by a single person swimming over or near the patient’s location, waves or ripples from a passing swimmer, splashing, water features and even wind or rain.
Lifeguards should understand the dynamics of dead water and adjust their line of sight and supervision strategies to prevent it. Identifying dead water at the beginning of a shift is important, as is the need to reassess throughout a shift as conditions change.
Other visibility barriers
Hypoxia, or lack of oxygen, presents serious limitations to a lifeguard’s ability to see clearly. When it sets in, the eye becomes less perceptive to details and contrast. The total field of vision becomes reduced, less can be seen out of the corner of your eyes and everything becomes dimmer. Some of the self-imposed stresses that rob your body of the use of oxygen include poor physical condition and cigarette smoking.
Lastly, Distraction is also barrier to effective supervision. A busy aquatic facility is full of distractions which are a common cause of incidents. Distractions can include patrons talking to lifeguards, mobile phones, excessive noise or dealing with problem swimmers. Lifeguards can also become distracted when fatigued or stressed, or by letting their mind wander. All of these factors can reduce a lifeguard’s concentration and ability to effectively supervise. Maintaining focus is one of the biggest challenges that lifeguards face during a long shift.
In addition to mitigating areas of Dead Water, lifeguards must also ensure they keep themselves in good physical condition and are not fatigued or unwell when turning up for a shift.