With the release of the NERD (Near Eye Remote Display), Shearwater Research has taken the concept of a rebreather head’s up display to a new level.
Rebreather Head’s Up Displays have never been HUD’s in the traditional sense. Unlike displays used in aviation that project actual information on a screen within the pilot’s view, rebreather HUDs have traditionally been simply an array of colored lights. It was not possible for the display to be mounted on the mask or DSV, because it was too close for anyone to read it easily.
In what can be described as an impressive feat of optical engineering, Shearwater’s NERD uses a series of lenses that create a ‘virtual focus’ on the display. This means that even when the NERD display is pressed up against the diver’s mask, the optical effect is similar to looking at a 32-inch television from a distance of 12 feet. Divers can look at the underwater world through their mask, yet glance at the information displayed on the HUD with a flick of their eye without the eye having to refocus.
Buttons for controlling the NERD are located on the left and right side of the display.
Some rebreather divers require reading glasses and expressed skepticism being able to read the NERD. More than once, we had heard, “That HUD sounds nice, but with my eyes, I won’t be able to use it.” With the virtual focal distance of 12 feet, most divers will be able to read it – comfortably. To be clear your old eyes will be able to read this HUD – unaided, with no eye strain, and easier than you read your SPG.
UPDATE: The production NERD also has a filter on the outermost lens – this filter prevents sunlight from being focused through the optics and causing harm to the display.
Diver’s who have ‘gauge reader masks,’ will also be able to use the NERD through their existing lenses, allowing the diver to use their existing mask to view their wrist mounted computers, gauges, and camera controls.
The NERD functions are equivalent to a Petrel dive computer. It meets the requirement of a redundant decompression computer. The NERD will be familiar to Petrel users with an identical layout and operation. A battery/brain box is attached to one of the breathing hoses of the rebreather. Piezo buttons on the left and right of the display allow for command inputs. Like the Petrel, the NERD can operate on several different AA sized batteries, including 1.5 volt alkaline, lithium, and 3.6 volt Saft.
For size comparison, the NERD (left) shown next to a rEvodream HUD (right.) The NERD measures 30mm x 75mm.
Underwater, the NERD may aid in improved buoyancy control. Holding a deco stop in the open ocean may be challenging at times. Having the depth-readout immediately visually available can make a world of difference when it comes to holding a stop without other visual references. During times when a camera, a reel or anything else keeps your hands busy, the NERD becomes invaluable.
A weakness of the NERD is it’s mounting bracket. The design allows for mounting on variety of different DSV’s however, it is overly complex. The loc-line neck permits for too much movement underwater. It is easily knocked outside one’s field of view; and one of our testers reported that it would move excessively while scootering. UPDATE: The Production NERD does have a shorter neck than the preproduction prototype pictured, and rEvo is now offering a a bracket which allows for the NERD to be securely mounted directly to the standard rEvo DSV clip.
Although at first the NERD appears to be expensive, it is not considering that it is a completely redundant computer and head’s up display combined. Additionally, having all the information available by just a change of glance, is a big safety improvements in rebreather diving. Photographers, videographers, and any diver who finds their hands occupied will greatly appreciate the hand’s-free capability the NERD offers.
Watch this video as Bruce Partridge from Shearwater Research explains the NERD.