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| Sailing during VRC Sailpast, May 14, 2016 (photo by Barbara on SV Berkana) |
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| Kayaking around Smuggler's Cove, May, 2016 (Pelagia anchored with stern tie). |
This post provides further information for cruisers considering/planning a cruise to Pacific Mexico. Preceding posts include: (i) Charts, Cruising Guides & Weather Sources for Mexico, (ii) C-MAP vs SEMAR charts, (iii) CM-93 vector charts, and (iv) using Google Earth and GE2KAP to create GPS-accurate GE image "charts".
UPDATE March 2022: See new post on "Best chartplotter and chart source for Mexico: OpenCPN & O-CHARTS"
UPDATE 2021(Jan): For the locations noted below, both C-MAP and Navionics now show the same updated details. However, the newer more-detailed SEMAR raster chart (but not included in the SEMAR vector set) for "the islands" in Bahia de la Paz (THE main cruising area for boats out of La Paz, BCS) is missing from CMAP and incorrect for Navionics (I prefer "no data" to "wrong data"!)
The differences noted below in this 2016 post show the kind of differences that can exist (the ones below are now corrected). The only way to know if a commercial chart is updated is to compare to up-to-date SEMAR charts.
2016 post:
In a number of preceding posts, we've noted that in some places in Mexico, "up-to-date" Navionics charts lack the updated detail found in "up-to-date" C-MAP charts.
Increased detail in a chart does not guarantee the chart is more "accurate"; however, it likely indicates the chart has added in updates from the official Mexican nautical chart supplier, SEMAR.
Below are several examples in the Sea of Cortez (and south to San Blas) where we've found Navionics charts lacking in detail compared to C-MAP charts. Readers may find the opposite in other areas (although we have not seen this).
In the examples below, the C-MAP image is always on top and the Navionics on the bottom. Each is zoomed so that the maximum detail available is shown.
La Palmita anchorage (south of B. Conception):
Cruisers should use multiple sources of information rather than relying solely on only one commercial chart source (e.g., Navionics or C-MAP). Given the relatively low expense of Navionics and C-MAP electronic charts, especially on IOS and Android platforms, it makes sense to use both (as well as charts from CM93, GE-image, Blue Latitude Press, and, if you have them, SEMAR).
Importantly, as we have seen up in BC waters, commercial charts such as Navionics and C-Map are often not up-to-date with official chart sources (and may take months to over a year to include an update).
Both Navionics and Jeppesen/C-MAP provide methods to report a "Cartography Discrepancy". However, these require some work to submit, and for large areas where a chart does not include the most up-to-date cartography provided by the official cartography office (in this case, SEMAR), it would seem the responsibility of the electronic chart provider to keep their charts for sale to the public up-to-date!
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| All of BC Coast (zoom in to view) |
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| Georgia Basin |
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| Rescue Bay: a favourite B.C. Central Coast anchorage |
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| Motoring up a windless Howe Sound on the way to Gambier Island -- still lots of snow on the mountains! |
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| View from Bert's Bluff over Port Graves, Gambier Island |
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| Zoom in on Pelagia anchored in front of Camp Artaban (taken from Bert's Bluff) |
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| View from Bert's Bluff across Howe Sound to the Lions |
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| Sailing out of Port Graves |
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| Sailing out of Port Graves (still lots of snow on the the Lions) |
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| Michelle removing Tacktick wind transducer (for quick repair) |
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UPDATE/COMMENT: This post concerning "CM93" charts is proving to be very popular. It must be noted that CM93 Version 2 charts are usually far from being "up-to-date"; certainly NOT the best charts"available, so users of these charts must be cautious. Often, they are totally out-of-date, and dangerous. In some cases, C-MAP or Navionics electronic charts (which are fairly inexpensive on Android and IOS platforms) may be more accurate. However, as we have noted in other posts, Navionics or CMAP charts may also not be fully up-to-date.
NOTE that Mexico's SEMAR issues new charts every year (as well as updates). For example, in 2018, SEMAR issued a new, detailed, chart for the islands in Bahia de La Paz. (Unfortunately, this chart is available only as pricey paper chart or Raster, and not in their vector/ENC collections (such as excellent O-charts).
THIS POST offers the best solution for electronic charting in the west coast of Mexico: OpenCPN, O-Charts Pacific Mexico, and Blue Latitude garbour charts, plus a couple SAT2CHART/SASPLANET charts to fill a couple "holes".
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CM93 vector electronic charts, covering the whole world, are shared widely among cruisers; they are also available from some sites on the web. Technically, these charts are "pirated", so user beware....
[Note: By "latest", we mean the most recent CM93 available which works in OPENCPN]
CM93 "version 2" charts are easily used in the open-source, freely available, OPENCPN navigation program (CM93 "version 3" charts do not work in OPENCPN).
When we were planning to sail to Mexico, a cruising friend gave us a copy of the CM93 charts. We were impressed that they covered the globe; we were less impressed when we saw their lack of detail. This was especially the case when we left the highly accurate (and free) raster charts of the USA and entered Mexico. In Mexico, we quickly learned (i) our CM93 charts were nearly useless, (ii) our updated CMAP charts (on our chartplotter) were much better, and (iii) in many (most?) places, even our up-to-date CMAP charts provided insufficient detail.* As we note in our earlier blog posts about charts and guides (as well as comparing official Mexican SEMAR charts with CMAP charts), we did not feel confident navigating close to shore until we reached Cabo San Lucas where we could finally use the excellent Blue Latitude Press cruising guides, with their excellent, detailed chartlets and accurate waypoints.
[*Our experience with Navionics charts in Mexico indicates they suffer similar problems as CMAP charts; indeed, we note areas where CMAP has important detailed updates not found in the Navionics. See our blog posts concerning CMAP, Navionics and SEMAR charts.]
It turns out, we were using a very out-dated version of the CM93 vector charts, dated mostly before the year 2000. Since returning home, we have found CM93 version 2 charts dating as late as 2012. The differences (improvements) over the years are substantial.
To help other cruisers, the examples below show the improvements in the CM93 charts for the years "2000", "2007" and "2012" (dates are approximate).
Turtle Bay/Bahia Tortugas (Baja California Sur)
Our first real experience with CM93 charts coming in to an unfamiliar bay.
Our circa-2000 CM93 chart was useless: no details, no depths, and the datum way off (on the other hand, the CMAP turned out to be pretty good).
The circa-2007 CM93 has much more detail and correct datum, although lights were not correct.
The circa-2012, CM93 chart shows an outline of the Marinas in the Sabalo Estero, but with few details. Fortunately, the combination of our CMAP charts and the Blue Latitude Press Pacific Mexico guide gave us the information we needed.
Other places in Mexico where CM93 2012 charts are inadequate (or useless) compared to official SEMAR charts:
The list is too long.
But, for example:
Puerto Los Cabos (San Jose del Cabo): nonexistent on CM93
Marina Coral (Ensenada): nonexistent on CM93
Marina Costa Baja (La Paz, BCS): nonexistent on CM93
"The Islands", Bahia de la Paz (new (2018) detailed chart): nonexistent on CM93
Topolobampo: details nonexistent on CM93
Bahia de Altata: details nonexistent on CM93
Marina at La Cruz and Paradise Marina (Banderas Bay): nonexistent on CM93
The list goes on and on....
CM93 charts in Canada?
After seeing these large changes (improvements) in the various versions of the CM93 charts, we wondered how the CM93 charts would look in our home waters in British Columbia.#
The circa-2000 CM93 charts are terrible for BC waters, even on the south coast of BC (even though most areas in 2000 were exquisitely charted by the Canadia Hydrographic Service (CHS) as well as preceding (mostly British) cartographers). However, by 2012, the CM93 charts are quite good.
Further north in British Columbia, there remain "pockets" of unsurveyed (or poorly surveyed) coastline -- almost all well away from typical routes. One area is "Lady Trutch Passage" on the Central Coast near Bella Bella. This passage always looked inviting, but was choked with narrow passages and no chart was available. However, in 2011, the CHS produced a new very detailed chart including Lady Trutch Passage. Interestingly, the circa-2012 CM93 chart includes this detailed information; the circa-2007 CM93 chart as a subset of this new charting; and predictably, the circa-2000 CM93 "chart" is hopeless for this area, even for the relatively well-traveled (and well-charted for years) "Perceval Narrows".
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| Circa-2000 CM93 "chart" for Lady Trutch Passage area: USELESS |
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| CM93 "2007" chart for Lady Trutch Passage area: VERY incomplete |
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| Pretty good, detailed CM93 "2012" chart for Lady Trutch Passage area |
Obviously, anything "new" since 2012 (marinas, rocks, shallows, buoys... etc) will not be correct on the "latest" CM93 v2 charts (approx 2012).
(# Legally, in Canada, vessels must carry up-to-date CHS charts, so technically, circa-2012 CM93 charts are not sufficient; of course, neither are CMAP or Navionics charts.)
Before we sailed down to Mexico, we wish we had been aware of the substantial changes in the CM93 electronic charts. We should have been... but we were probably too wrapped-up in too many things as we prepared to sail to Mexico, and as were were on our way down the coast.
Hopefully, some cruisers heading offshore will find this blog post helpful!
