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.
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.../ /...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.../
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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.