Wednesday, 23 July 2014

Information for cruising Mexico (charts, guidebooks, weather sources & communications) – Pelagia’s experience (2014-2015)

When we left Vancouver in August 2013, we had (what we thought) was a reasonable inkling of the various guidebooks, communications options and weather sources for Mexico.  After a season of cruising Mexico from Ensenada to La Paz, the southern Sea of Cortez, and Mazatlan, we now have a more critical (and detailed) view of options. It seems appropriate to share this with those cruisers planning to sail to Mexico this Fall (2014).

Note that these represent our experience and opinion – your mileage may vary.

All cruisers heading to Mexico have heard about the notoriously inaccurate/incomplete nautical charts in Mexico – with some cruisers suggesting many (most?) date back to the 1800s or early 1900s. While certainly true for a disconcerting number of charts, depending upon format, many regions have charts with excellent detail. Furthermore, accurate/up-to-date official charts (paper and electronic) are available from the Secretaría de Marina Armada de México (SEMAR) (see below).

Cruisers heading down the West Coast to Mexico typically have two or more of the following chart options:

  • Paper charts (most common seemed to be chartbooks based on NMA charts)

  • Electronic charting for onboard chartplotter (C-Map; Navionics; Garmin)

  • Electronic charting for computer for use with freely available (e.g., OpenCPN) or for-purchase (e.g., Fugawi; Nobeltec; Navsim) software using raster or vector charts. These charts may be the same as the C-Map, Navionics, etc chips, or may be the older vector CM93 charts that many cruisers trade with each other.
  • Tablet-based charts for IPad or Android (available for relatively low cost from Jeppesen/C-MAP or Navionics)

The USA "Defense Mapping Agency (DMA)"-based chartbooks were the only paper charts covering Mexico we could find while in San Diego; so, we purchased them. They are decades out-of-date, and for most areas, show far too little detail. We did not find them useful -- don`t waste your money.
We had an up-to-date C-Map card for our chartplotter (and computer), and also Navionics charts for our Android tablets.

[We also had older CM93 electronic charts (used in OpenCPN) and the DMA-based chartbook – neither showed acceptable detail or accuracy for coastal cruising/gunkholing. NOTE: make sure you have the latest version of CM93 charts -- approx 2010/2011 seems the latest date for Ver 2 CM93 (Ver 3 does not work in OpenCPN). There are major improvements between pre-2007 and later.]

Both C-MAP and Navionics have major areas lacking accuracy/detail. Some cruisers suggest one is better than the other – this may be the case for some specific areas, but for Mazatlan and the Southern/Central Sea of Cortez, we did not see significant differences. (Still, at little extra cost, having the “alternate” data set on the Android tablet was comforting.)  Unfortunately, none of the above charts had acceptable accuracy for the Pacific Coast of Baja. [Update: C-MAP 2014/2015 has reasonably good coverage for Ensenada and Turtle Bay.]

Last Winter, we overheard a cruiser stating that there was no use in purchasing chart card updates (e.g., C-Map) as their Mexico data had not been updated in decades (I think he said since the 1800s). This simply is not true. Our C-Map cards show clear changes over several updates (e.g. a few years ago, the C-MAP card did not show the “new” marina at San Jose del Cabo; our new (2013) card showed it clearly and accurately), and had considerably better detail (e.g., compare DMA paper versus C-MAP charts for La Paz). A quick check of the latest C-Map update (June 2014) shows substantially increased detail for Altata (north of Mazatlan) and, importantly, San Blas (south of Mazatlan); probably other areas too. Nevertheless, there were many areas with similar detail/accuracy (i.e., little) as the terrible DMA charts. 

UPDATE: The detailed charts in the Blue Latitude Press guides are available as GPS-accurate charts for PC, Android, IPad and Mac. The charts are the same price for all platforms; however, software required to view these charts is expensive for PC and Mac, but quite reasonably priced for Android ("PathAway") and IPad ("INavX") tablets. See Blue Latitude Press and Fugawi X-Traverse websites.

UPDATE 2015: C-Map updates show good detail for Altata, San Blas, and Loreto. Navionics charts do not show these updates [see this post]

Waypoints: The Blue Latitude Press cruising guides – the best guides (see below) – give waypoints for important routing, anchorages and dangers in the Sea of Cortez and for “mainland” Mexico from Mazatlan south. We have found these waypoints to be accurate and extremely helpful for navigation (of course, they are labelled “not for navigation”), especially when the electronic charts are lacking detail or accuracy. All of these waypoints are available for download from the BlueLatitude Press website  for a nominal (low) cost. We use the “gpx” format so that we can load these waypoints into OpenCPN (with CM93 charts) as well as transferring these to our chartplotter. (We’ve found the “GPSUtility program to be very useful for converting/transferring between differing formats/systems.)  Unfortunately, the Blue Latitude Press guides do not cover the Pacific coast of Baja (they hope to do so in the future).  Charlie's Charts and Rain's Mexico Boating Guide provide waypoints/anchorage coordinates for the Pacific coast of Baja.

OFFICIAL MEXICO CHARTS ARE AVAILABLE: The Secretaría de Marina Armada de México (SEMAR) produces its own series of charts, and these are available directly from SEMAR in both paper and electronic (raster) form for the same price. The SEMAR website  has a full listing of these charts, indicating their coverage, scale, and date produced/revised. I have seen some of these official Mexican charts and, at least the charts I viewed, they are considerably more accurate/up-to-date than the various electronic charting cards. Unfortunately, these charts are priced individually, not as a package. At 369 Mexican pesos each (plus tax) – about C$31 for either format – a full set for Mexico would be rather pricey. Another problem is that these charts are a little complicated to obtain: one has to contact a government chart seller (for example, in Ensenada: Estacion de Investigacion Oceanografica de Ensenada, B.C.,  Boulevard Costero y Agustín Sangines (A y B), Ensenada, B.C. 22800 Tel. +52(646) 172 57 43   EMAIL:  We plan to purchase some specific charts when we return to Mexico in October. [Update 2015: We borrowed a friend's SEMAR charts, but did not purchase any, as we had decided to return to the Sea of Cortez.]

Before we proceed on this topic, we have to be clear: Without a doubt, the Blue Latitude Press cruising guide series (two books) stand head and shoulders above the other guides:

Sea of Cortez: A Cruiser’s Guidebook (2009; 2nd edition)  [UPDATE 2015: a 3rd Edition is now available]

Pacific Mexico: A Cruiser's Guidebook (2010; 1st edition)

By Heather Bansmer and Shawn Breeding, Blue Latitude Press LLC, 

When we arrived in San Diego, we wanted to ensure we had the right cruising guides for the west coast of Mexico. After all, the navigation charts were "notorious" for being either/both inaccurate or lacking significant detail. We had already purchased two guidebooks – those by Heather Bansmer & Shawn Breeding (referred to above). These beautiful guides with beautiful photos are very detailed, with excellent chartlets and accurate waypoints.  However, the most recent edition was 2010, and they did not cover the west coast of the Baja peninsula. So we felt we should find other guides.We found two additional guides we hoped would fit these requirements:

Charlie’s Charts Western Coast of Mexico Including Baja California (2013; 13th edition)

Rains’ Mexico Boating Guide (2013; 3rd edition)

[There are also USA National Geospatial-Intelligence Agency (NGA) Sailing Directions covering the Pacific Coast of Mexico, available free to download. We had this but found them of little use.]
Those familiar with Charlie’s Charts, will know that these guides contain hand-drawn chartlets. The Rains’ Mexico Boating Guide contains smaller drawings/chartlets of harbours, etc. Neither book's chartlets could be considered, in our minds,  “charts". Nevertheless, we did use both going down the Pacific Coast of Baja; however, neither gave us confidence when navigating within sight of shore. 

When we rounded Cabo Falso (by Cabo San Lucas), we entered into the region covered by the Blue Latitude Press “Sea of Cortez: A Cruiser’s Guidebook”.  From thereon in, we had excellent guides with detailed chartlets. Combined with their downloadable waypoints, we felt much more comfortable navigating and gunkholing. At first (and occasionally later), we often “double-checked” information by also looking at Charlies’ Charts and Rains’ Mexico Boating Guide. However, we did not find these latter guides to be very helpful. Indeed, occasionally, their information seemed to us to be out-of-date, despite being published in 2013. By the end of our first cruising season, these latter guides were usually left on the bookshelf.


When we came down the Pacific coast of Baja (November, 2013), we felt uncomfortably limited in our weather sources for  Mexico. Used to "official" frequent, detailed and accurate forecasts for Canada and the USA, we could not find similar official forecasts in Mexico. (Occasionally, we would hear a Mexican Port Captain, such as in San Carlos near Mag Bay, read off a forecast – in Spanish, of course – but they were few and far between and hard to understand.)

We learned to rely on amateur forecasters, especially Geary of the Sonrisa Net, who provide daily forecasts via HAM (or any single-side band receiver) radio as well as via the web. These forecasts are easily available via Saildocs if one has a Pactor modem and either HAM or Marine-SSB Sailmail (see below). Also, many morning VHF nets (e.g., La Paz) provide forecasts, although I was never sure of their sources.

In April 2014, this situation looked like it would finally change for the better: NOAA (USA) now provides frequently updated text-based forecasts for reasonably/usefully small areas all the way down from the USA-Mexico border to Central America (and, to Ecuador, as well), including the Northern, Central and Southern Sea of Cortez. Currently, these forecasts are “experimental”, with limited or no human input -- essentially text summaries of GRIB file data;  nevertheless, they are very helpful.

[UPDATE 2015: they were scheduled to become official at the end of 2014, but this has now been delayed -- apparently indefinitely.]

NOAA Eastern Pacific Zones

Weather sources:

VERY USEFUL: Single-side band radio (voice):   

  • Sonrisa Net (3968 kHz LSB HAM; 7:30am Mountain time; weather at 7:45am)      
  • Amigo Net  ( 6212 / 6217 kHz USB Marine-SSB; 1400Z Daily; weather at 1415Z)
  • Southbound Net (8122 kHz at USB Marine-SSB; 0000Z Daily). [UPDATE JAN 2016: according to , the Southbound Net, which has been out-of-action for awhile, has started again. Now as an evening net.]

Single-side band radio (weather fax): less useful

Weatherfaxes do not provide detailed information for small areas of the Mexican coast, but they are excellent for seeing the big picture (and they DO involve a human forecaster). We did not use them often while in the Sea of Cortez. They would be useful for forecasting hurricanes (if internet access not available).

Easy to obtain with either the Airmail program or a program off the web such as JVCOMM32. A Pactor moem is not required. See NOAA for frequencies/schedules: (download “rfax.pdf”, which contains weather fax information for the world).

A complete set of relevant (to West Coast of Mexico) up-to-date weatherfax images can be downloaded very easily/quickly from the web.

VERY USEFUL: Single-side band radio (pactor modem) TEXT Forecasts: 

April 10th 2016 update: After not being updated for a while, the SONRISA NET Weather website is now fully functional,

Updated November 2014: Saildocs and Airmail now make it easier to obtain Sonrisa and Solmate weather forecasts. Both sets are now available in the Airmail "Text-Weather" window.

!! Airmail has an easy method to have text (i.e., small size) forecasts sent by Saildocs
  • Send an email to:, with line(s) in body of message requesting forecasts [no subject]. “Send” sends one time; “Sub” subscribes.    For example:  Send Sonrisa.Sea   [this sends Geary’s daily summary plus additional forecast info for the Sea of Cortez]
  • Sonrisa forecasts: see (Geary provides how to "subscribe" to his forecast using Saildocs and the full web URL. One can receive a  one-time sending of a forecast by using "send" instead of "sub".
  • NOAA (experimental):   Via Saildocs: "send"
  • Solmatesantiago (Stan, Amigo Net):Fore info see: [we found these forecasts less accurate for the Sea of Cortez]  
  • Other pages: In general, one can request Saildocs to send a text version of any page on the web. However, Saildocs will strip all images etc, and one might have to rename the text file received to xxxxx.htm and read the file into a web browser such as Firefox or Chrome

USEFUL: Grib files: 

For a warning about GRIB fioles, send an email to:

These relatively small-size files provide computer-generated weather forecasts – they are very useful but one must be cautious as they have no human (forecaster) input, and do not show shore effects. They can be downloaded from the web or via HAM or Marine SSB (Sailmail) from Saildocs. The Airmail program has a particularly easy-to-use Grib-request window.

Here is an example email sent to Saildocs to obtain information for the Southern Sea of Cortez: 
Line #1: Grib file; Line #2: NOAA forecast; Line #3: Geary’s Sonrisa Net weather summary; and Line #4: Stan’s solmatesantiago “southern crossing” forecast.  This email may be sent by regular web-based email, or by HAM/Sailmail SSB and pactor modem.

send GFS:34N,10N,126W,102W|2.5,2.5|0,6..96|PRMSL,WIND,WAVES|4.0,102,2014042515





We depended on four communication methods:

  • Cell phone: we obtained a TelCel SIM card in Ensenada. (Ask for an area code for somewhere south, where you expect to spend more time – we chose a La Paz area code).  Amigo Plan: If you purchase 200 MXN each and every 30 days, there are no long distance charges within Mexico, per-minute rates are the lowest, and long distance to the USA & Canada is very reasonable. However, one has to be sure to do this every 30 days. We found we did not use up 200 MXN each month, so ended up with somewhat more expensive rates. Note: no charge for incoming calls or texts.

  • Cell data: we initially purchased a “Banda Acha” data stick and SIM card, so that we could access the internet while cruising. We subsequently found that our Android phone with TelCel SIM card provided at least as good connection as a “hotspot” (allowing computer and tablets to connect via the Android wifi; IPhones do this too). So the banda acha stick is no longer needed. After a little research, we found it was easy to top up the data plan by web.

Cell phones worked often down the Pacific Baja Coast, in the Cabo area, and La Paz. Between La Paz and Loreto, cell coverage was nearly zero (OK at south end of Isla Espiritu Santo; very poor signal at Puerto Escondido).

[UPDATE: Cell coverage in front of  Villa del Palmar Beach Resort at Bahia Candelario/Ensenada Blanca, just south of Puerto Escondido is good]

  • WiFi: We found the WiFi at marinas more-often-than not to work poorly while on the boat. Purchase of a WiFi amplifier antenna helps substantially.
WiFi amplifier
  • !! Single-Side Band (voice and email): We especially found the combination of Single-side band radio, pactor modem and Sailmail made communication (by email) very easy, and possible almost anywhere. We would not want to be without it. (We found Sailmail to be much faster and easier to connect to than HAM Winmail.) We are not big “talkers” on the net, but we do enjoy hearing boat reports on the regular nets.
Of course, we also talked a lot in-person with other cruisers, often at sundown with a cold drink in our hands.

[We will update and revise the above, as necessary.]


  1. Another weather source for forecasts is We found this to be a good source for forecasts, as it does provide wave height and period, which are missing from sonrisa and erratically provided in noaa fcasts. It can be recd via email/saildocs as well. It is gribs based and automated, and does not give conditions.

    The noaa forecasts should become better next season as a forecaster is expected to be put on the case, until now they have been gribs based and without human intervention.

    Another useful resource is the southbound yahoo group, worth joining and subscribing to a digest of posts to get the latest news for cruisers.

    1. Hi Rob,

      Our post has the reference to -- pointing to the page explaining how to get these forecasts via email to Saildocs (whether by broadband internet or by limited SSB-based HAM/Sailmail email). We found these forecasts tended to under-estimate actual Sea of Cortez conditions (may be better for PV south?).

      Of course, as you've likely experienced, all of the assorted forecasts often missed actual weather.(For example, none seem to accurately predict coroumel winds in Bahia La Paz.)

      David & Michelle

  2. Hey Neighbors! I found this blog post at the top of a google search when I looked for Sea of Cortez weather! We leave La Paz to sail north tomorrow, and we finally have the SSB running and we can download GRIB files with the satellite phone--but I was looking for something more local, and I found this post. I have been attempting the more localized NOAA data, but no luck yet (I will keep trying.)

    Uly says he misses you, Michelle, and he's still dreaming about your beef stew! We have been in the marina long enough now that all the worker here know him by name and shake their heads in wonder at the amphibious dog...

    Jess & Josh, (formerly sv Far Niente, now Oleada)

  3. Hi Jess & Josh,

    Oleada = wave?

    Great to hear from you. Hopefully Uly hasn't done anymore of his "I'm outta here swims"! He remains one of Michelle's favourite dogs. We follow your blog whenever it is updated.

    Looks like NOAA is still only doing computer-generated forecasts for the SoC. So only Geary's daily/amateur forecasts have human input (listen to SSB or download text via Saildocs).

    What are you doing for charts? Highly recommend you get Shawn and Heather's waypoints (available digitally) and their electronic charts.

    We are enjoying home, with our ongoing tug-of-war between mountain activities (here in Whistler) and ocean activities on Pelagia. Mountains holding the edge, though we plan 3-to-4 weeks cruising to Desolation Sound in September (with sail friends we got to know in La Paz).


    1. Oleada = swell! Or one big wave. Or uprising. It depends who you ask.

      We are in Puerto Escondido now, what a beautiful spot! The mountains are incredibly green. The weather is laughably unpredictable, but we listen to the SSB and get friends to send us texts of anything big on the horizon, and I download the Pacific NOAA overview. Hurricane Linda just swept by hundreds of miles away, but it still dumped here for a couple of days. We will probably scoot out of here in the next few days and aim for Bahia de Los Angeles, with stops at Concepcion, San Juanico, and Santa Rosalia (I have been dreaming of the bakery there since we stopped on our drive down a year ago!)

      We have been using the Garmin charts, which were AWFUL between Espiritu Santo and here. We have Shawn and Heather's guidebook and plug in their points. I had no idea they have electronic charts!

      Uly has not been a fan of the thunderstorms, and although he almost always runs for the cabin these days, he did make an attempt to jump ship while we were underway on the north side of Isla San Francisco (fearing what, we never will know.) Fortunately, the dog overboard drill was averted. Otherwise, he has been happily eating and rolling in all the dead cochitos he could ever ask for on all the beaches up to here.

      I'm glad to hear that you are getting both mountain and sea time! We went to San Javier in the mountains here yesterday, it was such a treat!