What is the quietest DPV?

[Wookie]

I would thing the mag drive (Suex?) would be quiet.

 

[The Chairman]

I would thing

Is "thinging" a strong suit for you?

 

[The Chairman]

You'll never hear the end of it!

Not "hearing" it, is kind of the point, n'est pas?

 

[sunnyboy]

My buddy and I have go-pros mounted on our scooters (custom mount on the front of the scooter body). When listening to your own scooter on your own video, it's extremely loud due to conduction from the motor thru the body. Listening to your buddy's scooter through your video, it's much quieter.

That said, my P1 is very loud on my video, but much quieter on my buddy's video.

Anyway, my buddy dives a Gavin. You can hear the motor whirring, but it's quite quiet. The P1 is noisier, but it's also a totally different type of sound.

This due to the motor/prop configuration. The Gavin is direct drive with a (relatively) low speed motor. You can hear that very clearly. My P1 is a high-speed motor with the belt drive. Again, you can clearly hear the higher speed motor and the 'gearing' when it runs.

In a "who's the quietest" of the two, comparing videos of the other's scooter, I would say the Gavin does win rather easily.

 

[tbone1004]

I would thing the mag drive (Suex?) would be quiet.

suex is direct drive and the XK1 I rode for a few hours was on par with the magnus in terms of noise. Not terrible offensive, but more than my UV26. It had a bunch of other issues though for comfort and maneuverability.

The Genesis is the one you may be thinking of that does not use a traditional thru-hull shaft. It also has a countersunk motor
this is a decent video of a Genesis. It's not terrible offensive

 

[diversteve]

If I had to guess - I'd say a Genesis but I've never heard one run. The magnetic coupling should reduce some of the noise transfer from the motor - theoretically. Or am I thinking of a Suex?

I don't think it's a Cuda either - I was on a idve once and heard one coming a long way away. Thought it was a trolling motor or the ships pump till the diver flew by. I like their size though since If I get one I'll be flying with it.

 

[Superlyte27]

Pete, I have several Genesis you can borrow. It's as quiet as anything else, but longer burntime and ease of use makes it appealing.

 

[victorzamora]

@victorzamora will have to weigh in on the props as that is a huge part of what his degree was in in terms of noise/cavitation etc. of thin vs. wide blade props, number of blades, etc.

Actually it was just one report that was focused on underwater acoustic signatures of hydrofoils, but it was a very different case.

Either way, it's a complicated area. Enough so that "wider blades" or "more blades" likely won't have a simple explanation on how they impact noise. Theoretically, more blades will each disturb the water less but will become more likely to pass through disturbed flow. This will be louder than hitting just clean flow. As for wider vs thinner, there's variables both ways and I think that other factors in prop design (pitch, hydrofoil profile, fitment to shroud, etc) is a lot more of a factor than just blade number or width.

Also, I think that the prop isn't the main source of noise on a scooter. Listen to a good CCR+DPV video, and you'll find that the noise is a little too consistent to be fluidics. My guess is that the majority of the noise we hear as divers comes directly from the motor. This is backed up by the fact that, besides a little distortion, scooters sound much the same in the water as they do out of the water.

@The Chairman - Pete, Bonex has likely the quietest and least intrusive-sounding DPV. Tom and I disagree pretty drastically on the sound of a Magnus (he claims to be bothered by it, most likely out of jealousy of having a UV, while I find it to be different-but-similar to the UV/Viper series). Really, you'll need to see for yourself. Unfortunately, you may not get a good feel for it on short dives. Once I get into a "groove" on the scooter (which took me quite a while to get comfortable enough to develop), I find that the scooter becomes background/white noise and I honestly forget it's there. But again, you and I are different and you may never feel that way.

 

[The Chairman]

Pete, I have several Genesis you can borrow. It's as quiet as anything else, but longer burntime and ease of use makes it appealing.

When we diving? I'm out of the water 'till next Thursday.

(he claims to be bothered by it, most likely out of jealousy of having a UV, while I find it to be different-but-similar to the UV/Viper series)

That was chuckle worthy.

 

[Superlyte27]

Pete, want to do something at Ginnie next weekend? I'm teaching CCR in Key Largo tomorrow - sunday. But then I can be up your way most any time. I'll bring some toys.

Do you have an optima to use? Or want me to bring one of those too?