Navigation: Plans "A", "B", "C", ...

[Mirage35]

It's well known that I'm a "belt and suspenders" kind of guy - always want to know what my backup plan is. But then I started looking at my current navigation options.

- The iPad is now my primary tool and, because I wanted to try them, I have the option of iNavX, Navionics, and iSailor along with various charts.
- Secondary device is the old chartplotter with C-Map card in it.
- In case of problems or for amusement I also have Navionics on my phone.
- I carry paper charts, hand bearing compass, and other tools, and have experience in triangulation and navigation by DR.
- I am (for amusement only, be assured) learning to use a sextant.

AND ...
- At least 90% of my current cruising is within sight of land.

So, what do you think. Could this be overkill?

[RaymondR]

You can never overkill on nav equipment.

However, you seem to have missed out on OpenCPN and CM93, available for phone, tablet and PC. Handiest nav program ever coded.

I have a copy on a cheap tablet which I keep beside my bunk whilst at anchor to check that the anchor is holding if I wake up during the night. Just zoom it right in and press the track button and you see instantly what the boat has been doing whilst one slept.

[barnakiel]

Your primary tool should be your eyes and your knowledge of the local landscape.


You are 100% correct about having a 'B plan' and why not if you also have a 'plan C' then there is no problem.


HOWEVER, consider having plans based on DIFFERENT sets, e.g:


A - your eyes, your experience,

B - gps, plotter, etc.
C - a depth instrument and a paper chart with marked depths.


If you have a parachute and then a parachute and then one more parachute, it does not make much of an alternative if you happen to land in a lake.


b.

[GreenWave]

I think you are well covered and wouldn't chnage as thing asuming these are all familiar tools for you. Everyone has their preferences.

[Mirage35]

Originally Posted by barnakiel

Your primary tool should be your eyes and your knowledge of the local landscape.


You are 100% correct about having a 'B plan' and why not if you also have a 'plan C' then there is no problem.


HOWEVER, consider having plans based on DIFFERENT sets, e.g:


A - your eyes, your experience,

B - gps, plotter, etc.
C - a depth instrument and a paper chart with marked depths.


If you have a parachute and then a parachute and then one more parachute, it does not make much of an alternative if you happen to land in a lake.


b.

Well put. There I was being flippant and you go and add some thoughtful comment.

And if I manage to attach a picture I'll show one of my favourite shots of why eyeball MK I always takes precedence over the electronics.

[Mirage35]

Originally Posted by RaymondR

You can never overkill on nav equipment.

However, you seem to have missed out on OpenCPN and CM93, available for phone, tablet and PC. Handiest nav program ever coded.

I have a copy on a cheap tablet which I keep beside my bunk whilst at anchor to check that the anchor is holding if I wake up during the night. Just zoom it right in and press the track button and you see instantly what the boat has been doing whilst one slept.

Missed one - yes, I have also played with OpenCPN on a couple of systems at home, but don't have any devices on the boat that support it.

[requiem]

My suggestion would be to randomly disappear some of the components and see how well you get along. If you find that you end up not doing things you otherwise might, or that there's an unexpected dependency, then that's something to fix. Suggested scenarios might include: Tablet failure (random kernel panic?), GPS failure (no signal!), GPS position error (how will you detect this?).

One thing that makes me uncomfortable is that each of your devices is working with a different set of charts. I'm not sure I can do a good job of articulating the reason, but let me attempt a simple example: You have Chart Set A, against which you've validated the position of Atoll X using satellite imagery. You end up losing the device running Chart Set A, and switch to the backup with Chart Set B. Did you also validate Chart Set B's placement of Atoll X? Did you confirm that Chart Set B also has an appropriate scale chart for the area? If you plotted a danger bearing to keep you well clear of Atoll X, is it also displayed on the backup system?

Thus, whilst it's perfectly reasonable to refer to and compare a variety of charts during the initial planning phase, ideally the actual planning and navigation would be performed on a single set of charts. This single set, along with all annotations and other chart markups, should be shared across all your devices so that you are always working with consistent information.

As to your screenshot and Barnakiel's comment, you should always have more than one means of position fixing. Here's a suggested order of preference: visual, radar, gps, celestial. Remember, technology increases safety by putting more tools in your toolbox; it's the humans who decrease safety by not making proper use of them.

[Montanan]

“I have never been lost, but I was bewildered once for several days.” ― Daniel Boone.

[Mirage35]

In fact, I tend to flip back and forth between the various charts so that I'm comfortable with each and aware of their strengths and weaknesses.

And when going into a new area I treat charts like I do weather forecasts: when they all agree I give them a fairly high level of confidence; when they disagree I depend more on my own observations.

(A trick I learned for mountain hiking - don't know if it works sailing: always carry a deck of cards and if you get seriously lost, start playing a game of solitaire. Someone is sure to come along, look over your shoulder, and say "the black Queen goes on the red King", and then you can ask them where you are.)

[RaymondR]

One should always be mindful that all these electronic gadgets are known as "aids to navigation". A good knowledge of compass and chart work is also necessary.

[meirriba]

It is an overkill, so what? If you enjoy it it is fine...

[Cpt Mark]

Years ago I bought an airplane and the highest end Garmin portable GPS nav system and flew it back from MD to CA. Along the way I bought sectionals (air charts) as backup. All the people selling them asked why? Because if the gps fails I need to know where I am and where I'm going. Having lots of experience in the marine environment I knew that failure is inevitable.

Flying the magenta line was so easy. It didn't take long for my navigation by sectional skills to deteriorate. Those sectionals have way more info than our charts. Anyway, I started leaving the gps on but flying by sectional regularly to keep that skill up for when I would need it.

I view your approach the same way. Many will say it's overkill I say it's prudent. Sail using only 1 of each method so you don't get complacent.

[barnakiel]

No. Overkill is never fine. It is in fact quite the opposite.


Overkill introduces noise. Overkill introduces information overload and analysis paralysis.


Avoid excess. KISS. Use fewer tricks but master yours.


barnakiel

[billgewater]

I suspect that with all those options you may be totally absorbed and miss out on the sparkling sunlight, the moods of the ocean and the beautiful sky. Not to mention the bikini clad girl laying out on the fore-deck. Good navigation should be a tool to allow you to enjoy the sailing experience, not to smother it.
barnakiel got it spot on

[motion]

During my 50 years of flying I told my copilot if in doubt look out the window. Same thing on my vessel.
Get your head out of the chart plotter and look where
You are going. Be safe