May May 11th – San Blas, Mexico – Jim’s Blog #43

[Be sure to catch one of Sheilagh's infrequent blogs covering the "woman's" point of view immediately following this one.]

We left La Cruz on Friday, the one day of the week that superstition says one should never leave on a voyage. However, we were only continuing a voyage that started on Thursday; so we thought everything would be fine. As a matter of fact, it was fine except for the lack of wind. We had mild swells and enough wind to provide a cooling breeze as we motored around Punta Mita and headed north. In fact the weather was so pleasant that we decided to skip Chacala and go directly to San Blas.

We had enjoyed our previous stay at Chacala on the way down, where we had to use an anchor both at the bow (in front) and at the stern (in back) because there were so many boats anchored there at the time. This kept us from swinging into the other boats and it kept our bow into the swells in this very small anchorage. [I use the terms “front” and “back” for those who have no experience with boating terms, but are still attempting to follow this blog – why, I don’t know.] Chacala had very little in the way of restaurants, and, if you have been following this blog, you may remember that Chacala is where we got the chicken and beef that were too tough to cut – causing us to start eating fish at fishing villages, duh!

Bypassing Chacala only added three hours to what was to have been a six-hour sail. With the engine and the autopilot working flawlessly, it was a breeze to make San Blas with very little effort. We spent the day listening to music and books-on-IPod, and relaxing in the cockpit, as the boat did all the work getting us to San Blas. We saw a pod of dolphins pass on the starboard (right) side, but saw no boat traffic other than a few fishing boats off the beaches. The lack of other cruisers gives us the impression that we’re late for whatever event everyone else has gone to. Actually there was a cruiser celebration at Loreto in the Sea of Cortez north of La Paz that took place in early May; so many cruisers left us behind as we were vacationing in California.

[Sheilagh suggested I warn you that the next several paragraphs are navigation-specific, they caused her to lose interest in the first paragraph, and they might hold little interest for some of you. If this is the case for you, you may skip down to the next bracketed section advising you that my navigational meanderings are ended.]

I really enjoyed the trip up the coast on Friday despite the lack of sailing conditions because this boat is so totally impressive to me. It occurred to me that I have better and more redundant navigation equipment than I had on the P3B Orion in the Navy. In those days GPS hadn’t been invented and our other systems were not particularly helpful. We set up an inertial navigation system prior to every flight with our position at the airport, and it was supposed to track us throughout the flight if we fed it speed, drift, and any other variable we could throw in. I remember that it was almost always inoperative immediately after takeoff (I think the takeoff jarred it out of alignment), and it usually showed us hundreds of miles away from the airport where we landed after a typical twelve-hour mission.

We also had a Loran Alpha system that could be useful near the coast of the U.S., but could only provide us with an approximate line of position (it takes two lines of position crossing at a 90° to provide a fix). Modern Loran systems show a constant latitude/longitude readout, but that early system required that we have a large area Loran chart, identify which stations were covered on the chart, select two stations that could be reached by our equipment, tune the two stations together on an oscilloscope-like machine, superimpose the sine wave for each station, and read off a number that amounted to the delay in the signal from each station reaching us. Then we had to plot that line on the chart and search for two other stations that might give us a crossing line of position. In Hawaii and elsewhere in the middle of the Pacific there were never sufficient stations to give us two good crossing lines of position. Needless to say Loran was not a favored navigational device.

On longer over-water missions we used a sextant with a periscope that could be inserted through an opening in the overhead to track our position in relation to the stars. Since an airplane moves through the air in a corkscrew fashion the sextants were designed to take a reading on a star for a timed, 2-minute duration. We used an assumed position to select the three brightest stars in the sky that were in different directions in the sky. We would calculate where the star should be, then find it with the sextant (the constellations were always upside down in the sextant), start the timer, and attempt to keep the star in the center of the bubble with a knob that controlled the altitude for a full two minutes. We then consulted the Air Almanac and other volumes to get the position of the star over the earth and our distance from that star’s position on the earth.

That process took about ten minutes per star, and then we would “shoot” two more stars to get crossing lines of position. Even if we worked quickly and accurately and the lines of positions crossed reasonably closely to mark a fix, our aircraft was usually 20 to 30 minutes beyond the fix the navigator had just plotted. At an average speed of 300 knots or more, our aircraft would already be 100 to 150 miles past the fix when it was finally computed. When we returned from a mission away from Hawaii, we had to cross the ADIZ (Air Defense Identification Zone) at an exact time (within a few minutes), at a designated altitude (no problem), and at a specific position (5 nautical miles on either side was allowed). If we didn’t report everything accurately 15 minutes prior to coming through the ADIZ, the defense radars on the slopes of Haleakula would sound a warning that could cause interceptor aircraft to launch on us. You can imagine how frantic it got at the navigation station about an hour away from the ADIZ, when we had to rely on these now outmoded navigational devices – at that point the navigator was considered to be in “asshole and elbows” mode, huddled over the navigation table computing a star shot or standing on a seat as he shot a star.

The story is not all bad, however. The aircraft also had an ADF (Automatic Direction Finding) receiver that would point a needle on a compass card in the direction of whatever station was tuned in. When the navigator finally brought his ADIZ estimate to the cockpit, we pilots, who had been navigators ourselves, would look it over carefully and compare it to where we thought we should be, based on numerous previous missions like the one we were on. If there was any question regarding the navigator’s competence, we would simply tune in a radio station playing Hawaiian music, switch on the ADF, and the needle would point right to Hawaii. Then we would make a call as follows: “Hawaii Approach Control, this is flight Charlie-Delta-04 on a navigation training flight (indicating to the controllers that our estimate could be off quite a bit), approaching the ADIZ from 035°M at flight level 24, estimating penetration at 0410 Zulu, at an approximate position of latitude X and longitude Y.” That would cover us if we were not exactly where we said we were, and the ADF bearing got us in the correct quadrant for the air defense radars to see us and hopefully not launch on us if we were not in the exact window we had estimated.

Why did I go into all this navigation stuff above? Only someone who had to navigate with the equipment from yester-year, can appreciate the ease of navigating today. Now our boat has two installed GPS (Global Positioning System) units that show us our precise location on an electronic navigation chart (we also have a handheld GPS unit as another backup). To take a fix we simply look at either of the GPS units and plot the latitude and longitude on a paper chart we keep. We use the chart as a way to back ourselves up if our GPS units should fail, or if something should happen to the GPS satellites. We have a sextant as a backup, but we have yet to need it or use it, although we have a computer program that takes the place of the Air Almanac and the other volumes, in addition to doing all the computations for us.

[If you desired to skip my comments on my experiences with the navigation equipment of 30 years ago, you may continue here with very little negative impact on your psyche!]

I think of what we have now and what we had back in the 70’s, and I have nothing but huge respect for the sailors of old who ventured away from their homelands to discover all the lands that are bordered by the oceans of the world. We don’t have to heave-to with our sailboat when we come into a new bay or cove, lower the dinghy, and row slowly forward heaving a lead line with a weight on the end to see if the water is deep enough for our boat to anchor. We already have charts with all the depths of the bays and coves listed, cruising guides that discuss where to eat and what to do in each town, an automatic depth meter to tell us if the charts are correct, and a GPS that directs us to the exact mouth of an estuary as it did for us in San Blas. So I spent a lot of the trip up the coast thinking about how good we cruisers have it with the modern inventions we have today, as I listened to music on my IPod under the shade of our bimini, as the autopilot and the diesel engine kept us on a direct GPS line for San Blas. It doesn’t get much better than that, unless we could have sailed.

We made it into the San Blas estuary at about 5:30PM and found only four boats there. Previously we had anchored in Matanchen Bay, which is around a point of land from San Blas and requires a bus ride to get to the town of San Blas. Supposedly, by anchoring a mile or so from land in Matanchen Bay, cruisers can avoid the no-see-um bugs that descend in droves after sundown. This time we anchored right beside the town with a full set of screened portholes and a new set of screens for the hatches that Sheilagh had completed before we set out. Sheilagh settled on the use of Velcro strips on the inside of the hatches with Velcro-edged screens that can be put up or taken down very easily. Following instructions from the cruising guides, we sprayed all the screens with bug spray, closed up everything at dusk, and avoided the bugs quite well.

Saturday was Mother’s Day in Mexico, and today is Mother’s Day in the U.S. We will be going into town to an internet café so Sheilagh can call all our girls and allow them to wish her the congratulations she deserves for raising such great daughters. Of course we will also be congratulating our two daughters who are also moms, Melissa and Stephanie. More later . . .