Navigation Options For Offshore Cruising

[Kerry1]

Originally Posted by Burge

Hello,

I am preparing my boat for offshore cruising and don't know where to start with navigation options. Currently have a dated Navman with 5 inch colour screen which only has charts for NZ and South Pacific.

So what do people use who want an affordable option for extended cruising?

I looked at updating my chartplotter but the charts seem very expensive, so if you go with laptops or Ipads is there an affordable way of getting the navigation software and charts?

I have a Farr 44 just to give an idea of boat and size.

Thanks in advance for advice.

Anthony

Owning a Farr 44 and with the charts you do have sounds like you're in NZ or not far from it. I don't have offshore exp. but if you have a laptop, Open CPN seems a great software platform to me. For experiment I bought a cheap ($20) or so GPS dongle, and it works great. The other thing is that LINZ supplies raster charts for free that cover the South Pacific. And it appears that other nations do the same.Being not that technically savvy it was a piece of cake to download the charts put them in a folder that OpenCPN could access and the rest the program just handles so well.
Our boat was set up with Raymarine Chartplotter, Radar, Sounder etc, and I found a serial port to USB adaptor so hooked into the NMEA gadget so I simply plugged my laptop into that and was able to get all the info that was being displayed by the chartplotter in the cockpit after setting up the right ports.

The system will also accomodate AIS information as well.

Having said that and reading other posts by salts far more savvy than I, a knowledge of navigation outside of GPS would be indespensible as well as paper charts.

One never knows when the next solar storm will knock out all satellite communications, or when someone decides to turn them off.

[Mishiwa]

hi Burge

the cheapest way I have found is to download OpenCPN and CM93 charts to a laptop. OpenCPN is free but have heard that the charts are hard to get now. Check with other yachties in marina, someone will be able to let you have a set. I also like to have paper charts of the area I will cruise in, just as a backup if electronics fail. Some times you can get copies of official charts.

[Moontide]

I second the OpenCPN approach. Runs on Windows and iPads. Android version is in beta testing now. This ifree nav program is written by cruisers and is constantly being tweaked and updated.

There is also a free program called GE2KAP that creates charts from Google Earth images. More accurate than most of the charts that I have used. Commercial port charts are fine but the rest vary in accuracy. Not unusual to be anchored a mile inland with lots of charts, which is another reason I like the charts made using GE2KAP. Have not found a bust yet with those.

Mid ocean there is really no need for any charts. It is only land that will hurt you.

I happen to have a few paper charts on board but the state of electronic naigation is such that even the US (last country) no longer requires them to be onboard commercial ships. Guess I have 6 or 7 ways to get a GPS signal between the hockey puck gps units, smart phones, tablet, etc Throw a couple in the microwave (farraday box) when there is lightning around. Noting is totally safe with lightning, including a quartz watch, and drop a sextant and it may become worthless. I have a sextant, but it is more for fun and to aleve boredom.

If all the electronics fail I would approach land only in daylight and look for a local boat to follow in. Besides, the boat would barely be floating if I carried paper charts for all the harbors that I might go to, and the small scale charts for ocean crossings are pretty much useless near land.

My 2 cents for what it is or is not worth.

[lordgeoff]

Originally Posted by Moontide

I second the OpenCPN approach. Runs on Windows and iPads. Android version is in beta testing now. This ifree nav program is written by cruisers and is constantly being tweaked and updated.

There is also a free program called GE2KAP that creates charts from Google Earth images. More accurate than most of the charts that I have used. Commercial port charts are fine but the rest vary in accuracy. Not unusual to be anchored a mile inland with lots of charts, which is another reason I like the charts made using GE2KAP. Have not found a bust yet with those.

Mid ocean there is really no need for any charts. It is only land that will hurt you.

I happen to have a few paper charts on board but the state of electronic naigation is such that even the US (last country) no longer requires them to be onboard commercial ships. Guess I have 6 or 7 ways to get a GPS signal between the hockey puck gps units, smart phones, tablet, etc Throw a couple in the microwave (farraday box) when there is lightning around. Noting is totally safe with lightning, including a quartz watch, and drop a sextant and it may become worthless. I have a sextant, but it is more for fun and to aleve boredom.

If all the electronics fail I would approach land only in daylight and look for a local boat to follow in. Besides, the boat would barely be floating if I carried paper charts for all the harbors that I might go to, and the small scale charts for ocean crossings are pretty much useless near land.

My 2 cents for what it is or is not worth.

Realistically it is probably irresponsible to have paper charts and sextants as your primary navigation tool. Especially a new sailor who would spend valuable time and missed eyeballing to get an inaccurate position. Would any of us accept a GPS that was inaccurate between 5 and 10 NM?

[colemj]

Originally Posted by Moontide

I second the OpenCPN approach. Runs on Windows and iPads. Android version is in beta testing now.

OCPN runs on Windows, Linux and Macintosh, with the Android version in alpha/beta.

But it does not run on iPads.

If you want to run on iPad, SeaIQ is a brilliant app that I think is everything OCPN is. It uses CM93 charts, as well as almost all other chart formats you may have (BSB, S57, S63, KAP, etc). It will automatically download and overlay Google Earth photos and Grib files, has full Active Captain integration, great AIS functionality that presents crossing situations at CPA like Vesper does, and many other features. It costs $40, though.

I have no affiliation with SeaIQ other than being blown away by it as a user. The developer also has Windows, Mac and Android versions in development. I have the Mac beta and it is very far along.

For the record, I am also fond of OCPN and it is my go-to laptop charting program.

Mark

[Kiwi.]

Hi Anthony, I had a similar potential problem with an aging Raymarine with an old c chart. My solution has been two v1 iPad (Trademe $150 each) plus iSailor software and charts. These old iPads are super reliable. Just make sure you get the 3g version of the v1 iPad as the wifi only version did not have GPS. Why two? Because I store one in my metal box (a cashbox from Warehouse Stationary) that also holds our mobile phones, and satellite phone when we're offshore. A good metal box is your best protection against lightning strike which will destroy all electronics outside the box. (As an aside, if you don't have a metal box the oven works really well until your better half cooks your emergency electronics!) My old Raymarine is mounted outside as it's tough and built for the job whilst the iPad is mounted by Velcro by the chart table. We still have paper charts (small scale i.e. large areas) of the places we're visiting. They are great for planning activity for the days ahead and give a much better "feel" for the area you're in. Navigation by sextant is a great hobby to take up if you're going cruising; I do it, but that's what it is: a hobby.

[Burge]

Hi Everyone,


Great replys, so far I think I will try to get a few more c-map chips for my ageing Navman and then also get a ipad with Navionics and of course paper charts etc. Will also check out open CPN which quite a few people have mentioned.


Thanks for all the advice.

[DefinitelyMe]

Originally Posted by lordgeoff

Would any of us accept a GPS that was inaccurate between 5 and 10 NM?

If that GPS was completely independent of anything electrical or electronic, including the satellite network itself? Absolutely!

[lordgeoff]

Originally Posted by DefinitelyMe

If that GPS was completely independent of anything electrical or electronic, including the satellite network itself? Absolutely!

Permutations and combinations.
What would the odds be of say 3 backup GPSs and 3 boxes of A3 batteries (stored in the microwave) fail at the same time along with the failure of the GPS networks failing at the same time as you happen to be offshore sailing on an average of once a week in summer and never in winter.
Maybe one in a trillion trillion? I think I would choose an automated instant 3-5 Metre error over a 5-10 NM error manually calculated by a human in difficult conditions. Call me crazy........?
Hey start a thread on what Captain Cook would use to navigate if he had today's options?

[Jim Cate]

Lots of theoretical ideas from internet armchairs...

Here is my experience re GPS vs celestial:

1983... Ann and I off o n our first blue water passage: SF-Hawaii and return. No electronic navigation whatsoever. Found Oahu just fine, did some inter-island cruising, departed Kauai heading home. 21 day passage, but the last 11 days were total overcast, no sights possible. oh ****! Our DR had us closing the coast, one which is notoriously foggy at times. I was seriously worried, but one evening just at twilight it cleared long enough for a round of stars... what a relief! And we were only about 60 miles from the Farallones; our DR was about 30 miles out after 11 days.

Would I have used a sat-nav if I had one? My oath, yes I would! So all you pundits who worry about the remote possibility of total GPS failure and celebrate the good old ways... they had their problems far more often than do the modern versions, and left you just as blind.

jim

[barnakiel]

Yep. I would accept such a GPS. And Columbus would give his left arm for one too!

A 5 to 10 miles GPS could still be 50% more accurate than my solar fix on a rough day.

I say do not get hung up on electronics if you are going to sail long distances over open water - this applies especially to the South Pacific. Get a cheapo sextant and at least one quality mechanical watch just in case things get off the rail. Print out the almanac pages you will want for the time of the cruise.

We do not give up on wheels only because now cars have very reliable engines, do we.

b.