New DPV - Dive Xtras

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I drove mine for the first time yesterday. It was not difficult but there is learning involved. I towed one person almost the entire time and two people for a good bit of the time. It felt powerful. It is very light so the rotational force is substantial at higher speeds. When not using it, I clipped it to my hip and it "disappeared". I will really enjoy this scooter. The batteries seem to have a pretty substantial capacity. I will go again this afternoon. I am happy. I suspect scooter ignorance will soon be scooter bliss.

No trouble flying with it either. It definitely won't be impressive for those that have used well tuned and balanced scooters that cost 3-4 times as much. If I was going to be scootering around using it inside overhead conditions and on and off the trigger, this wouldn't be the scooter for me but I am using it to haul us out to the reef and back with it clipped off while we actually explore. For that it is the perfect 24 pound booster rocket. It is what it is. It isn't what it isn't.

On weighting it:
I removed both plates. I am using the Dewalt 12 AH batteries. I have 3 bolt snaps or double enders on it. At the surface it is just peeking out of the water. At 20 meters, it is perfectly neutral.
 
Thanks for the write up, Ray. Sounds like I got lucky and picked the right scooter for my intended use.
 
One other issue that bears further scrutiny and observation. At the beginning when I was holding the scooter and talking to my dive buddies, I was getting no reading on either tank on my Perdix and only one tank was reading on the Teric. Soon after getting underway the readings began to act normal with just a few odd dropouts. 5-10 minutes into the dive the tank pressures became consistent and remained so for the rest of the 99 minute dive. This may or may not have anything to do with the scooter. I suspect not. I will add some SPGs for todays dive.
 
I’d like to opt for the 12 Ah batteries instead. I just did three coastal swims last weekend of 2.5km each (no DPV) and was underwater for 120-137 minutes. The 12 Ah probably makes better sense since I enjoy exploring for longer durations. Also, if on a shorter dive, I’ll probably be towing somebody since DPVs are not very common on the southern Red Sea. The increased battery strength for the extra cargo will be good insurance.

In looking at one of my carriers back (Delta) to the Middle Heat, my Watt hour limitation is is 160 making the 9 Ah and 12 Ah out of tolerance.

More research.
 
I think you are mistaken on this point:

TSA wise, TSA will allow a battery with 100 watts maximum. That's a 5 Ah battery at 20 volts. But DeWalt gets around that with their 6 Ah, 9Ah and 12 Ah batteries as the protective travel cover on the battery activates a disconnect that separates the cells in the battery so that they are technically two separate batteries inside the case, each with less than 100 watts.

I'm trying to find this in writing on the DeWalt website so I can provide TSA and any potential carriers. Not finding anything like an SDS that clarifies the mechanical division of the cells.
 
I'm trying to find this in writing on the DeWalt website so I can provide TSA and any potential carriers. Not finding anything like an SDS that clarifies the mechanical division of the cells.

It's listed on the MSDS sheet

http://anchors.dewalt.com/anchors/_...lithiumionbatterypacks_en_msds.pdf?1584318982

(18 Volt/54 Volt) - DCB546 with Transport Cap. Battery pack is considered 3 batteries each having a Whr rating of 36 Whr with Transport Cap place in place
DCB547 with Transport Cap. Battery pack is considered 3 batteri each having a Whr rating of 54 Whr with Transport Cap in place
(20Volt Max/60Volt Max) - DCB606 with Transport Cap. Battery pack is considered 3 batteries each having a Whr rating of 40 Whr with Transport Cap in place,
DCB609 with Transport Cap. Battery pack is considered 3 batteries each having a Whr rating of 60 Whr with Transport Cap in place
 
- I think the feature where the speed setting gradually drops (1 every 5 seconds) when you stop is cool. But, if the current speed is below 3 and I stop, when I resume, I think it should stay on 1 or 2. In other words, I think it should never start up at a FASTER speed than what I was using when I stopped. I say this based on a specific experience I had today. I went into and through a plane they had on the bottom. An old Cessna, so it was small. I started in on speed 1. I got into the middle of the plane and stopped for a second. When I started up again, it came on at speed 3 and that was a major hassle. It was just too fast for where I was.

Probably easy for me to say at the 1atm of my stand up desk but if in confined space, wouldn't you just revert to muscle propulsion until cleared from the confined space?
 
It's listed on the MSDS sheet

http://anchors.dewalt.com/anchors/_...lithiumionbatterypacks_en_msds.pdf?1584318982

(20Volt Max/60Volt Max) - DCB606 with Transport Cap. Battery pack is considered 3 batteries each having a Whr rating of 40 Whr with Transport Cap in place,
DCB609 with Transport Cap. Battery pack is considered 3 batteries each having a Whr rating of 60 Whr with Transport Cap in place

The DCB612 isn't listed on that MSDS so I think trying to get them through TSA would be a potentially unpleasant gamble right before trying to board an international flight and having already kissed my wife goodbye curbside.

While one could reasonably postulate that the DCB612 is no more than 80 Watt hours (based on the DCB606 @ 40 Watt hours and the DCB609 @ 60 Watt hours), I'm not sure the TSA agent would be very interested in postulations.

It looks like the DCB609 (9 A hr) is the highest powered battery one can reasonably get through TSA and onto the carriers who have the prerogative to establish more restrictive standards than what the FAA has established for TSA to screen ( https://www.faa.gov/hazmat/packsafe/resources/media/Airline_passengers_and_batteries.pdf ).

The fact that I can get four DCB609s roughly for the price of two DCB612s doesn't hurt, either. Current sale is through Home Depot.
 
I was with @stuartv and another buddy Saturday, as Stuart said we were all new to scooters, we all purchased Blacktips and this was the first time we all had them in the water. @DA Aquamaster was aweseome enough to show up with his as well and give us some pointers, I feel like if he hadn't been there we would have all been second guessing our scooter purchases. The first few minutes were definitely humbling, but after a few adjustments to tow cord and a few changes to approach/technique it started to settle in and make sense.

At least 2 of the 4 of us had the DeWalt 12 Ah batteries, I had the Waitley 9 Ah batteries, I cannot remember for sure what the 4th person had. I found this to be very accurate:

Apples to apples a pair of 9Ah Waitley will only give about 80% of the run time of a pair of 9Ah DeWalt batteries. In turn apples to oranges, a pair of 9Ah Waitley batteries will only give about 60% of the tun time of a pair of 12 Ah DeWalts.

On the other hand, you can buy a set of 9 Ah Waitleys for $140, compared to $500 for a pair of 12 Ah DeWalts, and three sets of the 9 Ah Waitley batteries for just $420.

At just 60% run time per set of 9 Ah Waitleys compared to 12 Ah DeWalts, two sets gives you 120% of the DeWalt run time and three sets gives you 180% of the run time you'd get with a single set of 12 Ah DeWalts.


My first dive was a roller coaster ride, 40 minutes of up and down the gears on the trigger, we were on the trigger almost the whole time, and I spent extended time at speeds 5 and 6, popping higher than that for brief moments. Had I stayed on speed 3 or 4 I feel like I would have had a lot more battery left. I didn't check what my batteries were at between dives, I wish I would have. On the next dive I spent about 10-15 min at speeds 3/4 steadily before I really started to lose power. The Blacktip was at 2 bars when I got back in the water for Dive 2, after maybe 5-8 min it dropped to one bar. You could really tell when it began to lose power, I was in gear 4 and my buddy right behind me was keeping pace at speeds 1 and 2. Eventually it died so I hitched a ride with my buddy, as we got back I tried it again and was able to get a little more juice out of it, just enough to get me back to the dock. I pulled the batteries when I got out, one said 17%, the other 18%. The two with me that had DeWalt 12 Ah batteries still had plenty of battery power. The 9.0 Ah Waitleys having roughly 60% the run time of the DeWalt 12 Ah seems very accuarate to me. My original plan was to purchase 2 sets of Waitley 9 Ah, now I am rethinking that. I feel like with the DeWalt 12 Ah on most dives I do I wouldn't have to carry a second set of batteries. So it was definitely good to run the batteries to the end and see the true extent.

I had never been on a scooter before, so I don't have a lot to compare to, but so far I am impressed with this one, especially at the runtimes I saw with the bigger batteries. I am nowhere close to setting foot in a cave, so this scooter right now is plenty for me. A few things I would like to be different:

-The damn trim issue. It's honestly not enough to second guess the scooter, it's just enough to annoy me having to reposition it every time I let off the trigger. If a longer or different tube would offset this that would be awesome.

-I'd like to have more control over the speed settings, delays, start speed, etc. From what I understand the Piranhas are fully programmable like this, though I could have misunderstood that. I don't even know if this is possible with the electronics inside the Blacktip, but I would be interested in that, even if it was an add-on module.

All in all though, I am impressed after comparing this scooter on paper to others and then getting it in the water. Would I be more impressed with a Piranha P2? For sure. But it's not in the budget, it's not what I need for the diving I do, so it was never considered. At this price point this scooter was low enough priced that I could justify it as making sense in my budget even if it only goes out with me sometimes. I really feel like there wasn't a scooter out there until now that fit into this category, which may be a huge market - those who want more than an older Mako but less than a full technical DPV.
 
in NC, I can easily leave where I’m staying by 6 and not actually be on site to dive until 9:30 or 10. Some of the boat rides ARE long.

And if my last dive isn’t until, say, 2 (e.g. a 3 tank day out to the Meg tooth fossil ledge), how much battery will I have lost to all the time that day where I was not diving?

As discussed the other day, I intentionally left my 9 AH batteries in after doing some testing Wednesday evening (ending at 9pm) when they were at 22%, and noted a drop to 8% by the time I removed them to charge on Friday (at 6pm). That's a 14% drop in 45 hours, or roughly 7.5% per day.

Putting them in 4 hours per-dive would result in about a 1.24% loss on the 9Ah and about 1% with the 12 Ah batteries. That's not a significant loss and makes it very feasible to install batteries before you get on the boat or before you leave home to drive to a dive site as few hours away.

The critical issue would be not leaving them in the scooter after the dive for more than a day or two. Given that the BlackTip seems to slow down with about 20% showing on the battery meter, and start cutting off at around 17%, if you left the batteries in for more than a couple days, you'd run the risk of having the battery discharge to the point that it isn't recoverable.


...//...

.../ /...But, I have to say, the way it really wants to be pointing straight up all the time is really annoying and seemed like it was a lot to do with how hard it was to get the hang of. When I would try to turn, I would rotate the unit to have the handle in the direction I want to go. As soon as I would rotate the handle away from top dead center, it would feel like I had to torque the unit with my hand to keep the nose from pointing up. Today's experience really left me wanting to demo a scooter that trims out flat. It seems like it would be SO much easier to drive (and, especially, make turns).

I had a Piranha in the truck I would have happily let you demo. Let's do that next time we meet somewhere. I;ll bring our P1 and P2 to demo. They'll let you get a feel for a scooter that trims level and it'll let you see the performance difference. The P1 and P2 are about 30 fps faster, but the P1 has almost identical runtime when run at the same speed as a BlackTip, which means running at a faster speed comes at the cost of reduced run time. The doubled battery capacity of the P2 is very useful, not just for going farther, but also for going faster.

It's analogous to adding external fuel tanks on a fighter plane. It's not always about increasing range, but also about allowing the fighter to maintain a higher speed in the combat area to maintain a higher energy state. The same desire applies in a scooter, where faster (to a point - too fast starts to just be tiring) is often just more fun. I think that's why we are hearing about just the 9 Ah and 12 Ah battery choices and not the 5Ah or 6 Ah options among BlackTip users. (If the 12 Ah batteries were not significantly more expensive, it would be all about 12 Ah batteries.)

I seriously hope Dive-X comes out with a replacement tube that is longer and will let it trim out to be flat. And holds 2 more battery packs, if they're making it longer anyway. This scooter, if it would stay flat, and hold 2 more battery packs would be truly AWESOME.../

As a follow on to the "more usable speed, not just more range" comment above about larger battery capacity, doubling the battery capacity would indeed make it extremely attractive from both speed and range perspectives. It would increase the burn time from 120 minutes at 150 minutes to 240 minutes at 150 fpm, or alternatively it would provide an increase from 40 minutes at 215 fpm (Speed 6 in a single tank) to about 80 minutes at 215 fpm.

Oh, and, a couple of other things that occured to me to wish worked differently.

- when I double click the throttle to start it, it seems like the delay between the double click and starting to really pull could be about half as long. It's just long enough to make you sometimes think you didn't double-click correctly and start to do it again just as it was starting to come on.

- I think the feature where the speed setting gradually drops (1 every 5 seconds) when you stop is cool. But, if the current speed is below 3 and I stop, when I resume, I think it should stay on 1 or 2. In other words, I think it should never start up at a FASTER speed than what I was using when I stopped. I say this based on a specific experience I had today. I went into and through a plane they had on the bottom. An old Cessna, so it was small. I started in on speed 1. I got into the middle of the plane and stopped for a second. When I started up again, it came on at speed 3 and that was a major hassle. It was just too fast for where I was.

- I thought it would be nice if I could (accidentally, say) let off the throttle for just a second or two and be able to resume by just pressing the throttle again (rather than having to double-click it). In other words, if my thumb slips off the throttle for a second, or if I am changing which hand I'm driving with and I accidentally let go of the throttle for a second, it would be nice if I could just go back to holding the throttle button down and have it resume going whatever speed it was going, instead of having to double-click. If I stay off the throttle for more than, say, 2 seconds, then it requires a double-click to get going again.../
/...

I think that is excellent input. If you're operating the DPV at less than the cruise speed of 3, there is usually a reason, and as you point out re-starting faster could be an issue.

I also agree the pause before the BlackTip starts could be a lot shorter.

On the other hand, putting the two "bugs" together, the overly long delay does allow you to shift it down from speed 3 to speed 2 or speed 1 before it actually starts. Conversely it also allows you to shift up 2 or 3 gears before it starts as well. I did a lot of that in speed testing where I wanted to start off the line in a specific gear, where those bugs together ended up being a useful feature, once I figured out how to use them to my advantage.

Still, it would be great to make the start delay user adjustable.

Probably easy for me to say at the 1atm of my stand up desk but if in confined space, wouldn't you just revert to muscle propulsion until cleared from the confined space?

It really depends on the space.

With practice you can scooter cleanly through some very small spaces. For example, as a side mount cave diver, I'll scooter through low restrictions in high flow caves by just holding the DPV out to my right side so the overall profile of the scooter and myself is low enough to cleanly pass through a vertical space not quite 2 1/2 feet tall. Scootering through school busses or largish aircraft like the single GAF Nomad or the pair of Nomads that are found in Lake Phoenix and Fantasy lake, isn't hard at all.

The caveat here is that the space also needs to be silt free as in a confined space the wash from the scooter would otherwise blow the viz. If you blow the viz with a fine, clay based silt in a low flow cave, you'll blow the viz for hours. Even with heavier silt and/or in a high flow cave, it can cause problems for other divers behind you, so you still need to be courteous. Planes and busses in quarries usually see enough diver traffic to be virtually silt free.

Courtesy with a DPV is important. My full cave instructor commented once that Chris and Chrissy Rouse had blown the viz in a large portion of Ginnie using their DPVs. He made this comment in 2008, 16 years after they died, and it was still one of his most enduring memories of them. So keep that in mind when scootering not just in a cave or wreck, but also over any silt bottom where you might blow the viz. It's not a legacy you want to leave. In general, be sure that when you start, you don't have the prop pointing down at the bottom.

There are also times when a DPV cave diver might end up behind swimming divers in a small section of cave or in a swim through in a wreck, where you might want speed 1 or 2 to match their rate of swimming (or pulling and gliding in high flow) and still have to get off the trigger periodically to keep from getting too close. Here it can be very problematic if you get off the trigger for a few seconds and it then restarts in speed 3 and puts you right up on the other divers again.

Swimming the scooter is an option and in some cases (low or small and very silty passage) it is the only prudent and responsible thing to do. However, in other situations, like a section of a high flow cave where you need to pull and glide, it is not practical to pull and glide while carrying a scooter, and if it's just a short section where you can't pass, it's not worth clipping the scooter on to a D-ring to free both hands. Scootering at low speed makes far more sense in that situation.
 

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