I just wanted to point out that, the vast majority of the time, this kind of stuff happens with rental gear because the divers renting the gear fail to test it out
before leaving the dive shop. Whether you decide to rent regs or bring your own, you should be doing a
comprehensive pre-dive reg inspection including several functional tests. You should be doing methodical,
functional, pre-dive BCD checks as well.
Don't be that guy who rents a reg setup, brings it on-board, attaches it on the tank for the first time on the boat, turns on the tank valve, is shocked to find out that the second stage is free-flowing a little, and then complains about the deplorable state of rental gear. Such an issue should have been identified and sorted out well before boarding the boat.
Bubble, what about when the tanks are on the boat already? When I was in Cayman the tanks/weights/weight belts were on the boat. By the time I got my regulator hooked up the boat was already moving. After going off the back of the boat and swimming towards the line on my back, I realized I was getting splashed in the mouth too often with waves. Since I made the mistake of not bringing my snorkel (and the dive shop didn't provide one), I put my reg in my mouth, and swam face down to the line. The free flow occurred when I took the reg out of my mouth while waiting at the line. It was easily fixed, but I don't think I could have predicted it given that I'm a newbie and am anal about pre-dive checks. If you know something I don't, please speak up. I'm always willing to learn.
@
smurf doc: Have you taken a look at the
comprehensive pre-dive reg inspection link that some helpful SB DIYers put together?
It's a very nice list of checks to do, many of which could/should be done on rental regs
before the diver even leaves the rental shop.
You asked what could be done if the tanks are on the boat already. My answer is simple. Ask the shop for access to a tank with some air in it so that you can do your pre-dive checks on the rental reg
in the shop. I have yet to come across a shop that would not accommodate such a request. In fact, if you really think about it, you are actually doing them a
favor. You are ensuring that the reg is operational before taking it out on a boat. You are giving the rental shop an opportunity to fix a reg issue (or give you another rental reg) if such a problem exists. This significantly decreases the chances that your boat dives will be ruined by a reg malfunction. Not all boats carry a spare reg setup, you know. A busted reg could mean you sitting out a couple of rather expensive dives. In turn, you'll tell all of your friends not to patronize that dive shop "for having crappy rental gear."
At the very least, an in-shop reg check-up would identify frank free-flow at the surface and whether the cracking pressure is too high on the second stage. Personally, I won't tolerate a reg that breathes poorly. It detracts from my enjoyment/comfort during the dive.
When renting something like a scuba reg, it's important to remember that rental regs get used hard and require servicing quite often. Some rental shops take better care of their gear than others. OW students typically do a very poor job of rinsing out regs after a dive which can impact subsequent reg performance. Even rental shops that do a very conscientious job of reg servicing will have regs that require servicing before the next scheduled maintenance. This can be attributed to customer reg abuse or just being unlucky. Regardless of the cause, a customer renting a reg needs to be educated enough to do a fairly comprehensive reg check before even leaving the shop. In my opinion, OW instructors should teach their basic OW students how to do such checks since, in all likelihood, the students will be renting gear following certification.
With regard to specifically what happened to you...
I'm not convinced that there was really anything wrong with your rental reg. I have encountered many newbie divers who complained that properly tuned regs are "free-flowing." This occurs when the mouthpiece is pointing skyward and the reg is submerged in water. A well-tuned reg will begin to deliver air at 1.0-1.5 inches of water pressure. With the mouthpiece pointing skyward, this means that air will be delivered at or just before the mouthpiece gets below the surface of the water. To stop the flow of air, simply turn the reg over (so that the mouthpiece is pointing to the ocean floor). Another possibility is that the Venturi switch was set to "+/dive" while you were at the surface rather than "-/pre-dive." The Venturi feature creates a "suction" that maintains flow of air once it has already started -- you can see how this could give rise to undesired free-flow. Some regs have a breathing adjustment knob that can modulate cracking pressure, but in general this is a high-end reg feature which most rental regs lack.
The fact that you didn't complain of a free-flow issue prior to being in the water (at the surface with waves) leads me to believe that you didn't really experience a true reg free-flow. We can continue this discussion by PM if you have any other questions regarding this rental reg "incident." Alternatively, feel free to start a new thread in the "Regulators" equipment forum. There are lots of knowledgeable folks here on SB willing to help out.
On a side note, you'd be surprised how many people fail to do a comprehensive, functional pre-dive check of their BCD (rental or gear that is owned by the user). Not sure if this is out of ignorance or laziness.
PLus, that way you can "get to know" your sepcific reg, when it will free flow, etc
