The Dolphin Project: 2. Service and First Dives

I spent this past weekend with Course Director John Lachelt at Giglin’ Marlins in Houston. John is a Dolphin expert and one of the original factory trained technicians for the unit. He also previously owned a shop in Juno, Alaska, where he had a fleet of rental Dolphins. John is the man to see if you have questions about the Dolphin, and I’m lucky to have found someone nearby that was familiar with the unit. John and I started out testing and servicing the machine, and we immediately replaced the bypass hose which had split from being crimped in the box for 17 years. After a full going over, we put the unit in Giglin’s 14 foot pool for a test flight. John had one of the factory 100% orifices, and I had to try it. We topped off one of his original Drager 27cf cylinders with 02, and I eagerly jumped in. I was surprised how slow the flow rate was using 02, vice the other orifices, and it flows at only between 1 and 2 lpm. In the water, the Dolphin performed flawlessly. With the exception of a leaky BC LP inflator, all else checked out perfectly. I was amazed how little the unit vents on 100 percent 02. It truly feels like a CCR, and it’s actually quieter that my CCR’s. Of course there are limitations to the pool orifice, but using it in the pool is as close to a true CCR experience one can get with a SCR. Sunday we headed out to 288 Lake for a few dives. We switched to the 60 percent orifice, and although the gas venting was much faster than using 02, I was generally pleased with how it performed. I had only dived a Dolphin previously with 32 percent, and switching to 60 percent was quite a noticeable improvement. Other than the biting perch and the low viz, the dive was quite enjoyable. It was fun to get back on the unit, and I now look forward to some mods for it, and introducing some other divers to this classic machine. Next up, we will replace the “boat anchor” of an SPG with a more modern one, as well as adding a PO2 monitor connected to a Shearwater computer.