DPVs, Scooters - Toys or tools?

[tinman]

Diver Propulsion Vehicles (DPV) are not an item that many of us get a chance to play with. My basic question is what lessons have been learned and procedures adopted by what I see as the two typical users:

1) Tool people - yes the Teck crowd that use them all the time in caves and deep dark places where the Men in Black live.

2) Toy people - Rec divers that got their hands on one for a dive from a cruise boat or Southern vacation or LDS demo.

Us Lottery Winners in Waiting just need to know...

[Uncle Pug]

tinman once bubbled...
what lessons have been learned and procedures adopted
We are still learning to use ours as tools... but the fun factor will probably never disappear.

As a carry over from the other thread I do want to address the issue of tow behind scooters and the fear some expressed of having a run away.

Is that something you would like to see in this thread?

[tinman]

Certainly UP. Of particular interest would be runaway's in open/deep water. As a Nitrox user, I see the DPV as introducing a quick way for someone to get into trouble faster if you happen to be diving with a mix that is targetted for a particular area but then find your range increased with a DPV into a zone where you could hit higher partial pressures than planned if you hit the sand/mud in deeper waters. Of course, the issue of air consumption in deeper waters applies too.

Is there any difficulty maintaining control, heading with the DPV while also reviewing SPG/computer? Is this where multiple speeds or control with either hand comes in?

[dotyj]

Great thread.

Okay, many of you know that I use a powerchair for everyday mobility. No big news there.

My powerchair is a tool. Just about any modern powerchair will get me from point A to point B.

But my powerchair will get me around at speeds as high as 8.5mph, has active suspension, a really cool flame job, top of the line rehab seating, and is a hell of a lot of fun to drive. Sure it's a tool, but it's a tool I love to use.

That said, I can say in my newbie and humble (very humble) experience that a DPV is a tool. But the right DPV, much like the right powerchair can also be a blast (My powerchair is a Blast 850) to use.

My instructor had a good idea for keeping a console where it can be read by clipping it to the DPV. I can see this as a hazard though and I'm not sure I'd want to do it. Unless the console had a clip that would pull free if it got yanked on.

The DPV does cause some task loading which can be a problem. You have to monitor the battery indicator. I wouldn't want to drag a dead DPV around with me for half an hour or more. The DPV is capable of ascending at dangerous speeds.

I think with the right practice, most any diver can learn to use a DPV safely though.

[WreckWriter]

Definately a tool. Just yesterday we did a wreck in 150 FSW. The hook missed the wreck and by the time we got down had dragged 200-300 feet off. Had we not had scooters we likely would have done a sand dive.

Fun too for sure but also a lot of work as they are quite heavy on land.

Only one choice for brand, Gavin.

Tom

ps- No battery level indicator on any scooter I've seen. Neat idea though.

[Uncle Pug]

Tinman... OW runaway.... no problem... you don't have to let the thing take you up or down... you can, you know, go in circles. However this is why we use Gavins with clutches and variable pitch props. Reach in, grab the prop and stop it. While the clutch clatters away dial the prop pitch down to zero thrust. Mulitple prop pitches also mean that divers can travel together.... Shane has his on three to stay with me when mine is on one. No difficulty steering/handling a tow behind Gavin.

James... a tool... that you really don't need. On most rec. dives I expend very little energy... instead of swimming about madly, go with the flow dude. After you get diving down pat then you can use the tool to extend your range and gas supply.... however... this tool bites.... it can get you a long way from home... with a long swim back if things go sideways.


WW... batt level indicator... you don't need it... that is what your bottom timer is for.

[algorithm]

Well said uncle Pug

I use a Pharallon MK7 with variable speed. To make dam sure it doesn't run away or keep on going when I release the lever I installed an on/off switch dead center on the battery indicator plate. When I'm decoing on a wall on the way up and on mix, I don't care to be out of control or have move to any contingency table becase of scooter gone mad. I hear the new Pharallons to be released this January coming have a new prop and motor design and said to be fantastic, but time will tell. For me scooters are a tool but a very expensive toy.

Algorithm :boom:

[Uncle Pug]

algorithm once bubbled...
Well said uncle Pug


Algorithm :boom:
Hi Master Chief.... glad you were able to modify your Farallon enough to make it safe.

[algorithm]

Varoom Varoom Varoom.No No not Me uncle Pug.:bonk:

[tinman]

UP: There must be at least one mechanical engineer that's a diver! Is there not a risk that if you kill the engine vs. put it into neutral that restart at depth could be a problem? Big plus for Gavins vs the competition I would think.

PADI: I'm amazed that DPVs haven't been added to the Specialities list...everything else has. A new revenue stream just waiting to be branded, packaged & priced. Sorry, one of my former lives was as a New Products Manager - slipped out of diver mode for a minute, sorry for the lapse (I'd be happy to write the business plan for a price!)

So Gavins have a couple of votes (well, let's say three, UP you're worth a couple of votes in my book), and MK7 with a kill switch gets second, any other contenders...

[Duncan Price]

Tool (like the rest of my dive gear - except the rebreather which is a toy) - though also great fun.

I have a 2nd hand Mako with beefed up nose plate - several friends have bought DPV's and then sold them because they don't use them enough to justify ownership and simply enjoy swimming more.

Duncan

[tinman]

If in open water on a reel at 15 feet doing a safety stop/deco, how negative are DPVs? Or do you just do slow circles watching your depth gauge. Do you shot your lift bag instead and if so, is a 50 Lb bag enough? Do you need to use some of your drysuit or BCD lift as well.

[WreckWriter]

tinman once bubbled...
If in open water on a reel at 15 feet doing a safety stop/deco, how negative are DPVs?

Your DPV should be weighted to be neutral. Mine hangs beside me clipped to my crotch strap. It gets in the way a bit but you get used to it.

Tom

[Uncle Pug]

WreckWriter once bubbled...
Mine hangs beside me clipped to my crotch strap.
Ours are just a touch negative (ounces) in salt and hang down out of the way.

[WreckWriter]

Uncle Pug once bubbled...

Ours are just a touch negative (ounces) in salt and hang down out of the way.

Obviously that has advantages but I like mine neutral because we generally ride down to the wrecks then clip off the scooter, often in a place where you wouldn't want it to sink as it would then be inside the wreck.

I think its a preference issue based on typical dive type.

Tom

[dotyj]

I agree UP:

The DPV I'm learning to use will travel at up to 3 knotts. Way too fast for just keeping up with my dive buddy.

I think the instructor was mostly concerned with me being able to comfortably keep up with my dive buddy or deal with currents.

I doubt that I'll need a DPV very often. I can't justify the cost of one, and don't really want to pay to rent one if it isn't needed.

Towing a dead DPV isn't my idea of fun.


Uncle Pug once bubbled...
James... a tool... that you really don't need. On most rec. dives I expend very little energy... instead of swimming about madly, go with the flow dude. After you get diving down pat then you can use the tool to extend your range and gas supply.... however... this tool bites.... it can get you a long way from home... with a long swim back if things go sideways.

[Uncle Pug]

You won't find any current in Hood Canal. And you should restrict your diving to non-current areas... relying on a scooter to replace swimming strength is a bad idea IMO.

As for keeping up with buddies... buddy teams should be taught to move at the pace of the slowest individual... it is not up to the slowest to keep up... it is the responsibility of the other(s) to *stay with.*

That is why I said learn buoyancy control and alternate finning techniques. Most folks thrash around frenetically because if they quit moving they sink or pop... hopefully you can find a buddy who also has enough buoyancy control that they don't need to be in constant motion.

[FLL Diver]

tinman once bubbled...
PADI: I'm amazed that DPVs haven't been added to the Specialities list...everything else has. A new revenue stream just waiting to be branded, packaged & priced. Sorry, one of my former lives was as a New Products Manager - slipped out of diver mode for a minute, sorry for the lapse (I'd be happy to write the business plan for a price!)

Obviously you haven't checked them out in awhile. ;)

http://www.padi.com/english/common/courses/rec/continue/diverpropulsion.asp

Marc :jester:

[tinman]

FLL: I stand corrected. Another business opportunity missed...

[mddolson]

3rd user: The DIY project builder.
Designs one, builds one,(why: cause he can) tests it , parks it, and moves on to the next project.

I've got one.
Welded aluminum cannister,
2 x 2 speed shakespear trolling motors.
2x 12volt 25 AH Gates sealed lead acid batteries.
1 toggle switch main power,(and secondary kill switch)
1 toggle switch hi/lo speed
1 spring loaded dead man on/off switch. This is on an ikelite camera control rod to a DC angle grinder trigger switch.

It's ballasted in fresh water (with a 3 lb wt) to be be 1lb negative, so you could have it 2 lb possitve if you like.

Tinman if you're intersted PM me, and make m an offer , it's just collecting dust in my work shop.
It runs at about 2 mph on hi and 1 mph on lo speed settings.
It needs a little work, one battery has a dead cell I think.

MikeD
:blfish: