Can Anybody See Me? Visibility Underwater

By Rubicon Foundation editorial team

5 min read · 22 October 2026

Can anybody see me? is a 2001 journal article by Wallbank A addressing underwater visibility and the question of whether a diver can be seen. Visibility matters because divers rely on sight to orient themselves, maintain contact and communicate; understanding its limits is relevant to both diving practice and the science of underwater perception.

Why is being seen underwater a difficult problem?

Seeing a diver is not simply a matter of looking in the right direction. Water absorbs and scatters light, reducing contrast and obscuring objects, while suspended particles can create visual haze. The resulting view depends on the water and lighting conditions as well as the distance between observer and diver.

Visibility is also reciprocal only in a limited sense: a diver who can see another person may not be equally easy for that person to detect. Background, viewing angle, movement and the visual attention of the observer all affect whether a diver stands out. The article’s title frames this practical question as one of detectability, not merely how far a person can see.

What determines whether a diver stands out?

Light reaching an observer has to travel through water, reflect from the diver and return through the water to the eye. Absorption dims the scene, while scattering redirects light and lowers the clarity of edges. These effects make colour, contrast and outline important: an object that blends into its surroundings can be difficult to distinguish even when it is nearby.

Conditions vary with the environment. Natural illumination, artificial lights, water clarity and the visual background can all change how conspicuous a diver appears. Movement may help attract attention, but it can also be missed if the observer is looking elsewhere or if the scene is visually complex.

Contrast: how clearly a diver’s shape differs from the surrounding water or background.
Distance and viewing angle: both affect the apparent size and clarity of a target.
Light and particles: illumination, absorption and scattering shape the view.
Attention: an observer must be looking in the relevant direction to detect a diver.

Why does visibility matter for diving safety?

Visual contact supports coordination between divers and helps a group stay together. When visibility is poor, a buddy or surface observer may not notice a diver who has moved away, even if that diver can still see the rest of the group. The same limitations can complicate navigation, supervision and the recognition of a developing problem.

Underwater visibility is therefore part of a broader safety picture, rather than a guarantee of effective communication. Divers use agreed procedures and appropriate equipment to manage the possibility of losing sight of one another. Planning must take account of the actual environment and the limits of visual observation.

How does this subject fit into diving research?

Research on underwater visibility connects physical optics with human perception and operational practice. The physical environment determines what light reaches the eye; the observer’s attention and ability to interpret the scene determine what is noticed. Studies of detection can therefore examine both the underwater conditions and the task an observer is trying to perform.

The subject is relevant across recreational, scientific and professional diving, as well as to people responsible for diving medicine and hyperbaric care. Understanding how divers may become difficult to see helps frame questions about separation, observation and communication. Wallbank A’s article appeared in the SPUMS Journal in 2001 as a modified reprint from DIVER in 2000, placing it at the intersection of diving practice and the professional discussion of underwater safety.

What should divers take from the visibility question?

Visibility should be treated as a variable condition, not as a fixed property of a dive site. A diver’s confidence in seeing others does not establish that others can see that diver. Environmental changes, orientation and attention can all alter detectability over the course of a dive.

This is a general educational discussion, not individual medical advice. Divers with health concerns relevant to underwater activity should consult a diving-medicine physician; operational decisions should be based on suitable training, planning and conditions.

Frequently asked questions

What is the central subject of Can anybody see me??

The title raises the problem of whether a diver can be detected underwater, a question shaped by visibility, contrast, distance, lighting and observer attention.

Why might a diver be hard to see underwater?

Water absorbs and scatters light, which can dim a scene and reduce contrast. A diver’s background, angle, movement and the observer’s attention also affect detection.

Who may find this topic relevant?

It is relevant to divers, scientific divers, diving physicians and hyperbaric clinicians because visual contact can support coordination, observation and safety planning.

Citation details

Title: Can anybody see me?
Authors: Wallbank A
Year: 2001
Published in: SPUMS Journal 31(2): 116–119
Record type: Journal article
Repository record: Rubicon Research Repository, handle 123456789/7727

This page is an original summary written by the Rubicon editors from the publication’s bibliographic record. It does not reproduce the paper, its abstract or its data; consult the publication itself for its methods and findings.