Looking at scooters to help with long surface swims to dive sites

[cetacean]

All,

First, apologies for not reading all the threads re: DPVs, but I'm trying to figure out if a DPV is even a useful consideration for the following situation...

Most of my diving is in warm, tropical water - not looking for a DPV for this. I'm specifically looking for a DPV to help with the lengthy surface swims I often face in Monterey Bay in Northern California for local diving.

As I get older, I'm starting to be less tolerant of cold water, so my~60 min dives are turning into <40 min dives in Monterey. Anything that helps me get to the descent point (edge of a reef, edge of a kelp bed, etc.) with less effort means I'm going to enjoy the dive more, and be able to focus on underwater photography (I'm always carrying my camera) when I get there.

I'm also assuming it can help on the surface swim back (where I'm often colder and little more tired).

A few questions:
1. Are there DPVs that can be useful in this fashion? (helping with surface swims?)
2. Are there any powerful enough to pull 2 divers? (we often dive in our group of 4, could we get away with 2 DPVs?)
3. I'm not planning on riding through kelp, but a number of our sites have kelp beds, which means we often have stray kelp fronds floating randomly on the surface... any DPVs deal with this kind of stuff better/worse than others?
4. We are trusting sort of folks, so we would likely leave a DPV roped onto a piece of kelp, descend, do our dive, and then return to the DPV (floating?) for the return swim in. Possible?

Other than using several DPVs in the past (recreationally) I don't have a lot of knowledge here, so looking for any help/guidance available.

 

[Nick_Radov]

A few questions:
1. Are there DPVs that can be useful in this fashion? (helping with surface swims?)

Sure, any DPV will work on the surface. I use a Suex but pretty much anything (other than one of those little pool toys) will be fine.

2. Are there any powerful enough to pull 2 divers? (we often dive in our group of 4, could we get away with 2 DPVs?)

Any reasonable DPV can pull 2 divers, with somewhat reduced speed and increased battery power consumption. So your range will be significantly reduced relative to the manufacture's specifications.
Towing on the surface is a bit awkward but can be done. The problem though is what do you do if one scooter fails? Better make sure that everyone is capable of safely swimming back.

3. I'm not planning on riding through kelp, but a number of our sites have kelp beds, which means we often have stray kelp fronds floating randomly on the surface... any DPVs deal with this kind of stuff better/worse than others?

They're all terrible when dealing with stray kelp fronds. The more powerful units can chew through a single strand but really you should look where you're going and avoid them. In any sort of thick kelp canopy it's easier to run a few feet below the surface.

4. We are trusting sort of folks, so we would likely leave a DPV roped onto a piece of kelp, descend, do our dive, and then retun to the DPV (floating?) for the return swim in. Possible?

It's possible. I've never heard of someone stealing a DPV but I guess that could happen. Personally I would keep it with me throughout the dive to ensure I don't lose it. You can clip it off and disable the motor when you're not riding it.

 

[lostsheep]

Nick has covered your questions but I’d like to bring up a couple of points as a Monterey DPV guy myself.

Many people find DPVs make them colder because they aren’t exerting themselves.

Some of our best diving really benefits from long scooter dives; maybe just embrace it? What dive site(s) are you thinking of?

I’d keep the dpv with me. Someone just lost a Genesis, we don’t need to lose anymore.

 

[macado]

A lot of good points already made. One thing about DPVs is they can very quickly get you into situation where you are incapable of swimming back to your entry point (due to distance or gas constraints). If you're just talking single tank diving and using the DPV to "assist" that can be helpful but you need to make sure you have enough "gas" to swim back in the event of a scooter failure. I know it seems obvious but a lot of people forget this. It's a bit different than an overhead environment where you "can" surface but it doesnt always mean that the surface is the best option. I do a lot of shore DPV dives where I treat the surface as a virtual overhead due to the amount of boat traffic in the area. Surfacing to me is a last option. I plan to have enough gas to swim to shore or everyone in team has a DPV and can tow/assist in the event of DPV failure.

There is however a big difference in performance/capabilities of a $400 SeaDoo DPV compared to $8000-9000 Suex/Seacraft/Genesis/etc. I'm honestly unfamiliar with Monterey so maybe a Seacraft Go or new little Suex or even Blacktip would probably suffice. In New England we try to avoid long surface swims due to boat traffic but maybe it's different in NoCal?

It does not sound like you are planning to go very far but my point about gas planning still applies. A DPV can get you very far away from your entry point quickly. You may not plan for this but it's easy to be a little over zealous on the trigger and end up in a situation with a failed DPV and current you are unable to swim against.

1. Most DPVs can be used on the surface but it's going to far more comfortable scootering underwater. Sometimes easier to swim a few feet under the surface with a good compass attached to the scooter.

2. You can easily tow another diver but at the cost of reduced speed and much higher drag and battery consumption. I'm of the opinion that everyone in the team should have a DPV. If buddy teams get separated or you have a scooter failure it means now you have no one with a scooter. That is not a great situation if you get caught in current or even up much further from your entry point than planned. Scooters are also more fun with a buddy.

3. A lot of high-end DPVs have removable props that you can easily remove prop to dislodge kelp. But I try to avoid weeds / kelp when scootering. Sometimes it's unavoidable and I end up pulling weeds out of my prop but you just need to be careful.

4. Do not leave the DPV unattended. Sure, maybe clip it off on a wreck somewhere but the DPV should be with you at all times. I would not leave one unattended on the surface. A properly weight / neutral DPV is really not a big issue to clip off to you.

 

[Jon Nellis]

All good replies, but if by "help on the surface swim back" you mean with your head out of the water and breathing free surface air instead of back gas from a regulator, that is not what you should plan on. DPV's operating at the surface will pull down air and "ventilate" the propeller when too close to the surface. Additionally, the forces on your body partially out of the water will make it much more difficult to control. You should not plan on breathing surface air, even with a snorkel, during your transits in/out, especially pulling a buddy.

The bonus of a DPV is that your air consumption goes down significantly, since you are not swimming. Expect at least a 50% increase in dive time, once you get your breathing under control.

Since you are not swimming on the surface, it is a lot easier to get through the kelp 5-10ft underwater, not to mention staying below boat traffic. Some DPV brands have weak propellers and a reputation for breaking blades. Do your research. The Genesis will chew right through most kelp, but feather boa kelp is much tougher and should be avoided to prevent twisting it up around the prop, requiring a stop to clear it.

You will get colder, since you are not generating as much body heat by swimming. Add more insulation to your drysuit and a commensurate amount of lead. Dry gloves help a lot, along with a warm hood.

A lot of our customers mount their cameras on their DPV and simply take pictures while it is still mounted on the DPV, unless you are trying to get really close macro.

The joy of DPV diving is just getting out and exploring, covering more distance and seeing more areas and creatures. Take a camera for the occasional exceptionally cool discoveries, but save the majority of pictures in your mind, not on a hard drive that you'll likely never look at again.

Cheers,
Jon



.