On 03/02/2015 12:22 PM, Joakim Bygdell wrote:
On 02 Mar 2015, at 5:51, Steve Butler <[email protected]
<mailto:[email protected]>> wrote:
On 02/27/2015 10:54 PM, Joakim Bygdell wrote:
On 27 Feb 2015, at 21:23, Steve Butler <[email protected]
<mailto:[email protected]>> wrote:
Now, as an OC rec diver (soon to have access to the 100-130 depths)
I would not want to enter the ascent segments separate from
spending time at a level on the way up in order to indicate to
ascend at best rate. Take this scenario:
Drop to 130 and hang there for 6 minutes (28% O2).
Rise at 30'/m to 70 and hang there for 8 minutes on the ledge.
Ascend at 30'/m to 40 (no wait as it is a transition to an upslope.
Spend 5 minutes swimming the upslope to 15.
Spend the standard 3 minute stop at 15.
As this is a multilevel dive you have to do some calculation on your
own, i.e transition times between the levels.
That is what I was hoping to avoid. Especially as we entice more
newly certified OW and AOW divers to use Subsurface. Use of the
printed dive planner and the eRDP both assume the transition time is
included in the "level" time.
That is because they assume that each level is represented by a square
profile.
If we take your example dive in reverse creating a dive your students
might be called upon to do.
Assuming you start from shore with a 7 min slow descent to 70’, spend
7 min @ 70’ followed by 5 min swim upslope to 15'.
How do you plan such a dive on the tools you mentioned?
Do you ignore the time not spent @ 70’ or do you calculate the average
depth for those 12 min and use a square profile as a representation?
If you use subsurface in your classes, teach the students to use it
properly the way it was designed,
do not try to imitate how the eRDP works because subsurface can do a
lot more.
In which case the check to drop to first depth (which combines the first
two lines) is really not that useful at best and possibly misleading
when looking at what was entered. It led to my losing the 130 depth on
a dive with a 70' ledge on the way up.
Entered (with check box off)
130 7
70 2
70 10
Noticed the profile and saw that I'd failed to check the drop box. So
clicked that first box and got:
70 9
70 10
Now, if I enter the original list with that box already checked and then
uncheck it I get:
130 2
130 4
70 2
70 10
Which is what I should have entered in the first place (though I would
have done 130 5 on the 2nd line).
Which makes me think that if we're going to enforce entering all way
points, then the "drop to first depth" box really isn't that useful and
in my case, while I an learning the interface, caused me to lose my
initial depth line.
Final DepthDurationRuntime
13022descend
13068level
70210ascend
70616level
15521swim upslope
15324stop
When you do that the ascent rates that you can set tin the lower
left cornet of the planner will not be used.
The descent rate will be used only if you check “Drop to first
depth”. And in this case it will replace the first two lines with this.
13088
Containing both the descent time and the time spent at 130’.
This is what the OW rec diver expects to enter.
See above.
Oh, and option to pick between 15 or 20'. I noticed only 20' was
set as the last stop.
That is because the planner used 10’ increments in its internal
calculations.
And the planner will only calculate what reamins on the ascent after
your last waypoint.
OK. How about another check box to "include 3 min safety stop at 15
feet" at the end of the dive. At least that is what is being taught
in PADI.
That might not be to hard to implement.
Compare how the planner works on your example vs. a blue water
ascent profile.
The only thing entered into the planner is this line with “Drop to
first depth” checked.
Final DepthDurationRuntime
1301313
In this case the planner will tell you that the calculated ascent
from 130ft, using the defined ascent rates, will take 7minutes.
Multilevel dives you have to define all waypoints for all the
levels, until the start of the ascent that contains your safety stop.
In the first example if the upslope didn’t exist your last waypoint
would be @ 70’ and the planner would calculate the ascent time to
the surface.
Since you don’t have any deco obligation it will tell you that you
can ascend to the surface using the defined ascent rates over a time
of 4min.
Would still want the option to add 15' 3 min safe stop without having
to calculate the ascent times.
/Jocke
--Steve
/Jocke
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