Banderas Bay, the new sonar transducer, lithium batteries, Garmin charts, etc. tech(ish)

We are in Banderas Bay.  After new years eve in Punta de Mita and a few days at anchor near La Cruz de Huanacaxtle outside Marina Riveria Nayarit, we are now at dock in Marina Valarta and visiting family on vacation…

Banderas bay has four marinas and a couple pretty good anchorages to choose from.


  • Marina Riviera Nayarit,,
  • Paradise Village Marina,
  • Marina Vallarta,
  • Nuevo Vallarta Marina,


  • Punta de Mita – not bad for a few nights
  • La Cruz de Huanacaxtle – most popular , services at marina, dinghy dock $40 peso/day
  • Yelapa – a bit rolly sometimes, you can find a mooring from a panguero


We put the Garmin GPSMAP 840XS into Hajime in December and it worked fine as a replacement for the GPSMAP 3206 which it replaced.  Since it had the GPS integral, all we were worried about were the power +/-  power leads and the NMEA data leads in the connector so we cut the old one and spliced cables to do the hookup!  No trying to run cables up the binnacle.  The sonar was another issue, we (OK, just JIM really) have been wanting a fish finder/sonar at the helm and not just a depth sounder.  With the GPSMAP 840XS we opted for the GT21 hoping we could figure out a way to mount it inside the hull and shoot through for operating.  We did this with the Garmin GPSMAP 441, our backup chart plotter/ sonar, and with the Navionics T-Box transducers (

We did do the in-hull mount and so far all looks to work well.  Tested the unit with some clay to make a dam with water around and under the transducer to see if it worked and it was seemed fine but we were in the marina at dock…  In the end, after finding a tube of sealant in the hardware in Mazatlan which turned out to be water soluble, cleaning that mess up and finding a tube of silicon in San Blas, we just stuck it down on a blob of silicon, being careful to get NO AIR BUBBLES in the silicon under the unit.

Lithium Batteries:

I mentioned in an earlier blog that this year when we returned to the boat the voltage on the 400 Ah lithium battery house bank in Hajime was at resting voltage of 13.22.  We had isolated these batteries from charge and discharge back in early April 2017 when they were at a resting voltage of 13.54 volts.  We are pretty pleased with the store-ability of these batteries.

At present they are still acting as they were when installed a couple years ago.  Seems like for each Amp Hour you put into them you get an Amp Hour back out.  We will do a capacity check this season and report it in the blog.

The last capacity check I can find recorded was March 3, 2017    321 Amp Hours capacity from 13.6 to 12.6 volts.  I seem to recall an informal one we did to around 315 Amp Hours as well but have no documentation…

Mar 03, 2017 CAPACITY TEST:

Using the Victron Energy Precision Battery Monitor BMV-702S we run capacity testing on our 400 nominal Amp Hour house bank.  NO CHARGE DEVICES, AVERAGE LOAD 5 to 20 Amps

  • 3/3/2017
  • 7:00 AM 13.18 V (volts) at -54 Ah (Amp Hours)
  • 4:00 PM 12.98 V at -160 Ah
  • 11:00 PM 13.01 V at -185 Ah
  • 3/4/2017
  • 7:00 AM 13.01 V at -191 Ah
  • 8:00 AM 12.90 V at -200 Ah
  • 12:00 PM 12.87 V at -230 Ah
  • 1:00 PM 12.83 V at -245 Ah
  • 2:00 PM 12.83 V at -253 Ah
  • 3:30 PM 12.80 V at -274 Ah
  • 4:00 PM 12.80 V at -280 Ah
  • 4:20 PM 12.75 V  at -285 Ah
  • 5:00 PM 12.78 V at -290 Ah
  • 6:00 PM 12.75 V at -302 Ah
  • 7:00 PM 12.70 V at -310 Ah
  • 7:30 PM 12.60 V at -321 Ah


Garmin Charts VUS021R California and Mexico G2 Vision Chart card:

Have been working with Garmin charting on the VUS021R chart card data, At least I feel like they are listening.  We had the 1999 Garmin charts on the GPSMAP 3206 when we first came down in 2012. The word on the street was to watch the charts very carefully when in MX waters.  Our paper charts had references to like 1890 surveys on them too.  We had an Android tablet and the Navionics charts when we docked in Ensenada in 2012 and they were excellent and have proved so ever since.  No they do not cover everywhere with exact detail and we still use the local knowledge you get from a cruising guide as well but Navionics was much more current that the Garmin charts.

I decided to give Garmin another try, purchased a 2015 copy of VUS021R this year and reviewed it to find it was little changed from the 1999 info we were use to.  The satellite imagery was helpful, but the sounding data was of little help.  I went to the Garmin submit an error site: , and sent in a couple issues.  The missing Marina Mazatlan in Sinaloa for one and missing all of Puerto Angel bay in Oaxaca.  I did get a reply from Garmin within a few weeks to say the 2017 charts had included the Marina in it’s updates.  Buffeted by the response, I’ve also sent in information on the missing Fonatur Marinas, all 7 or 8 of them hoping they would include them in the 2018 release.  So with confidence in my heart, I purchased the 2017 VUS021R G2 Vision charts chip.


I have since downloaded the 2018 v.19.5 data and installed same. Good and bad, Mazatlan did get covered, Puerto Angel as well.  None of the Fonatur Marinas are in the data and Banderas Bay is a mess.  All around the bay and at Punta de Mita and  Cabo Corentas the soundings, shoreline, light and buoy locations are very inaccurate.  DO NOT USE THESE CHARTS FOR NAVIGATION!

I have continued the correspondences with Garmin and will let you all know how it goes from here.

Some photos with satellite overlay showing some chart issues…


The missing marinas:




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