| A series of experiments were conducted to determine the manual performance, information processing, visual and perceptual capabilities of divers in simulated operational environments. Results were combined to develop comprehensive ergonomic guidelines for underwater equipment and displays. These guidelines were used to optimize the display of information and to evaluate three different underwater displays for mine countermeasures (MCM) divers.;Three methods of communicating information between the diver and dive supervisor were evaluated. Results showed that the current rope-pull system is difficult to learn and inefficient. An intuitive coding system using an electronic keypad proved both faster and more accurate (p<0.05).;The effects of pressure (40 msw), elapsed time (0, 5 and 120 min.) and complexity on the ability of divers to process and recall information was measured. Results showed decrements in information processing and recall due to pressure, elapsed time and complexity of information (p<0.05). Recommendations were made for changes to procedures and equipment.;Experiments were conducted to determine the optimal font size, colour, contrast, and background for underwater displays. Subjects viewed displays in light, dark, clear and turbid water conditions. Results indicated that font height should be ≥ 6 mm and the display should have a black background with a light orange or light green foreground.;Experiments were designed to quantify the manual performance capabilities of divers, and the deficiencies caused by wearing neoprene gloves, exposure to cold (4°C), narcosis, and pressure (40 msw). Results showed a ≤ 60% decrement in tactile sensitivity and manual dexterity when wearing gloves in cold water (p<0.05). Measurements of hand skin temperatures indicated that neoprene gloves did not provide adequate insulation at 40 msw. Results were used to design and test keypad controls for divers.;Ergonomic guidelines developed from these experiments were used to design functional, integrated display layouts for MCM divers. Three prototype underwater displays (head-down, head-mounted monocular, and head-mounted binocular) were evaluated by MCM divers at surface and at 42 msw. Although divers were capable of using the displays effectively, results showed differences in performance between types of display (p<0.05). Each display showed unique ergonomic design problems that compromised performance.;Keywords. Environmental Ergonomics, Design Guidelines, Underwater Displays, Diving, Diving Physiology. |
