I tried the new hoses last Monday. They worked great. I basically couldn’t tell they were there.
We did two dives; the first one to 85 ft in Sebago Lake and the second one we stayed in shallow water were my wife got to practice a compass course between three buoys.
We also got to play around practicing buddy breathing (more on this experience below) and I played around taking off my tank underwater to check the flexibility of the hoses.
• The hoses are very flexible but rugged. They will not collapse when you stretch and twist them (either buddy breathing or taking of my tank over my head and looking at it in front of me).
• The hoses are very heavy. The outside diameter is larger than the conventional USD hoses, but they seem to be so heavy that buoyancy is not an issue. If anything they may actually be a bit less buoyant.
• The breathing performance is at least as good as my conventional hoses, but I can’t really say that it is noticeably better. My experimental Royal breathes so well that to notice any minor improvements would have to be a side by side comparison. Looking down the inside of the hose, it looks like a more uniform air duct since the convolutions are closer together, but it is hard to tell how much of a difference that would make. When I get a chance, I will try to see if I can measure any side by side resistance difference with my Magnehelic gauge.
Over all the good points are that the hoses are very comfortable and perform well, but now for the bad points.
• They are ugly, but as an engineer, I can easily ignore looks as compared to function. Also looks is definitely on the eye of the beholder. I agree with Nemrod: “perhaps an acquired taste”.
• They are very…very hard to dry. I ran air from my hose dryer set up (a hair blower on cool, look at this link for picture:
viewtopic.php?t=851&postdays=0&postorder=asc&start=15) through them and another pair of conventional hoses for over an hour. The conventional hoses are very dry. The new hoses seem dry, but I stick my finer deep in the corrugations and they are still wet.
I will try drying them further tonight, but when relaxed the convolutions tend to close and air may never flow into them enough to dry them well. Maybe if I stretch them a bit. I am thinking that the easier solution may just be the occasional use of something like Leistering mouth wash (or something similar) to control any potential bacterial growth.
This reminds me, one thing I notice; my hoses have a distinct mint smell to them when I was breathing. It was kind of pleasant, but weird. Has anyone else notice that?
Over all, IMHO the hoses are great, but the issue about moisture and bacteria growth can not be ignored. I think it can be easily dealt with regular cleaning and drying the best possible. I would like to thank Sam Miller for pointing this potential issue.
About buddy breathing, the hoses worked well, but I forgot to instruct Christine with some important details before we practiced. I forgot to mention to her that with my curved mouthpiece, when it is up side down, if you don’t blow all the water out, you are drinking it. The position of the mouth piece opening provides a small sump for the main user if there is any water, but during buddy breathing the receiving diver needs to deal with the upside down mouthpiece.
We will practice buddy breathing with my double again. But, that exercise convinced me that if I am diving with a mixed group of divers who are not very well practiced in buddy breathing specifically with a DH, an octopus can be very important.