Oxygen Addition Oxygen addition on the KISS rebreathers is what we call a buffered manual control system. The oxygen is added in two ways. Via the manual add valve, continuous flow and manually. By continuous flow: The manual add valve holds the 0.0035 orifice. Once the oxygen valve on the cylinder has been turned on, there will be a constant flow of oxygen into the rebreather at all times. The flow rate is adjustable and can be set as high as 1 liter per minute. But most divers will want to keep it around 0.5 to 0.7 liters per minute. The flow rate is just enough to keep the diver from becoming too busy underwater. What does this mean for the diver? When he reaches his desired operating depth, the PPO2 is manually adjusted and brought to the appropriate level. As long as the diver isn’t working hard or moving up and down in the water column, oxygen will be added infrequently. How does a diver determine where the flow rate should be set? The simplest way is to go diving. Are you constantly adding gas, even while at depth, when you aren’t working hard or moving up and down? If this is the case, then the flow rate should be increased. Are you finding that the PPO2 is slowly increasing during normal diving activities? If yes, then more oxygen than the diver can metabolize is flowing into the loop. The flow rate should be reduced. Manually: Oxygen can be added to the loop manually by pushing the manual add valve button. In general, when the valve button is not depressed, the oxygen is forced through the 0.0035 orifice at a steady rate. When the button is depressed, it is like a door has been opened and a larger amount of gas is allowed through the valve. The diver will push the button more at shallow depths and less at deeper depths.
		Jetsam PPO2 Displays The Jetsam displays have three independent, backlit PPO2 displays. Each display has its own housing, battery and sensor, making the system completely redundant. The batteries are user changeable. Each display can be replaced independently and spares are easily affordable.
		Scrubber Canister The Sport KISS scrubber canister has a bi-axial design. It is a durable canister which has 2 easy to fill openings and holds approximately 5 lbs (2.3 kg) of absorbent. Sofnolime 797 grade of absorbent was used for testing. The gas flows from the exhaust hose into the canister and lung below, and then passes through to the next canister and lung, and back out the inhalation hose. The canister is accessed by removing the pod safety clips and then removing the red hose attachment pods. Once removed, the canister can be pulled up and out of the counterlung case. The counterlungs are attached to the bottom of the canister. The canister comes complete with 4 plugs which allow the diver to pre-fill the canister. Spare canisters are available for purchase.
		Counterlungs The Sport KISS uses 2 back mounted counterlungs which are available in 2 sizes. They are attached to the bottom of the scrubber canister. Back mounted lungs leave the diver’s chest area clear and reduce the number of hoses and fittings compared to the over the shoulder counterlungs found on other rebreathers. These lungs are manufactured by Jetsam Technologies. The Sport KISS comes standard with 2 medium lungs. Smaller lungs are available upon request. As the counterlung case has a plate to adjust the size of these lungs, the diver is able to closely match their own lung volume with that of the Sport KISS. This plate has 5 positions. With the Sport KISS rebreather, it is important that the counterlung volume match the diver’s tidal volume. This will give the diver exceptional buoyancy control and eliminate the risk of overfilling the lungs. It is also important that the rebreather sit tight and as high up on the diver’s back as possible for the best work of breathing (WOB). A high WOB can be caused by an ill-fitting harness which allows the unit to float away from the diver’s body. Also, overfilled lungs will float away from the diver’s body, causing a high WOB as well.
		Bailout Mouthpiece The Sport KISS Dive Surface Valve (DSV) has a built-in bailout 2nd stage regulator; this means that the diver can go from closed circuit to open circuit with a twist of a knob. The knob on the DSV is used to either open the rebreathers breathing loop or when closed, allow the diver to breath in open circuit mode. The DSV can provide the diver with an alternate method of adding diluent gas or even an alternative diluent depending on the connection. It is a simple way to purge the rebreather for verifying the sensor readings. Also, it can prevent panic in the case of a malfunction in the rebreather by allowing a fast, simple way of getting your next breath. NOTE: * The diluent bottle is not adequate bailout. When diving a rebreather, a separate bailout bottle should always be carried.
		Automatic Diluent Valve The automatic diluent valve (ADV) on the Sport KISS is used to draw the diluent gas into the breathing loop. A diluent gas is necessary as the loop must be filled with a breathable gas mixture. As we drop in the water column, the gas in the loop compresses and the volume left will not be enough to breathe. The volume of the loop will also be decreased as you metabolize the oxygen When the volume of gas in the loop has decreased, the diver simply inhales hard to trigger the ADV. The operation is similar to a 2nd stage regulator. Suddenly finding yourself unable to get a breath during a rapid descent could be a panic inducing situation. The ADV will help eliminate that as no hands are required to trigger it. The diluent gas can be air, nitrox or trimix. Generally air or trimix are normally used and the nitrox is reserved for shallow applications, such as pool demos or shallow reef diving. Diluent can be added several different ways: ADV: Using the ADV to add diluent gas to the loop is simple and convenient as it has a hands-free operation. This valve is triggered when the gas in the loop has either compressed or the loop has been breathed down. DSV: Diluent can also be added two other ways using the DSV. First, the diver can close the breathing loop completely and go to open circuit mode. The diver takes a breath off open circuit and then opens the DSV and exhales the gas into the loop. Lastly, diluent can be added by turning the knob on the DSV towards the closed position only 1/4 inch, for a couple of seconds. This will cause the second stage to trigger and gas will blow directly into the loop.
		Cylinders and Attachment Methods 13 cuft cylinders are the best size for use with the Sport KISS. As the limiting factor on a rebreather is the scrubber duration, this provides plenty of gas. A 13 cuft oxygen cylinder will provide 5 hours of oxygen at a consumption rate of 1 liter per minute. A 13 cuft diluent cylinder will provide enough gas for an experienced rebreather diver to do two, 1 hour long dives to 150 ft. Jetsam highly recommends that you carry more gas than just the diluent. It should be in the form of emergency bailout, open circuit gas in a separate cylinder. A larger diluent cylinder is not an adequate bailout gas supply. Other advantages to using 13 cuft cylinders are the size and weight. They fit the Sport KISS well and have good balance. They are easy to travel with to a local dive spot and also pack easily in a suitcase for an over seas trip. The Sport KISS uses a custom designed cylinder mounting system. This mounting system has been designed specifically for aluminum 13 cuft cylinders. Cylinders of the same diameter and a similar weight can also be used.