The Gulf of Tehuantepec, Mexico

29 April 2013

by Tuuli

The Gulf of Tehuantepec looks small but can pack a punch.

We had planned to regroup in Bahía Huatulco, clean the diesel out of our stinking bilge, do some weather planning, then make the long trip through the Golfo de Tehuantepec to Puerto Chiapas, which is only 14 miles from the border with Guatemala. When we arrived on Sunday at Marina Chahué, the crew from Ashika, Dois and Lauri, whom we had met in Zihuatenejo, told us that a "weather event" was brewing in the Tehuantepec and was due on Friday.

The Tehuantepec (sort of pronounced teh-oo-WHAN-na-pec) has a reputation that makes mariners of all kinds, even those in the big boats, perk up and pay attention.

If there is a high pressure system over Texas or the Gulf of Mexico and a northerly wind in the Bahía de Campeche (Gulf of Mexico), wind can pick up speed through a gap in the mountains of the Mexican isthmus and make conditions dangerous in the Tehuantepec. It can kick up gale and hurricane-force winds with very steep, short-period waves (the period being the number of seconds between each wave) in the Gulf of Tehuantepec at any time of year. The waves can build to dangerous levels hundreds of miles out to sea. These gales and storms are called Tehuantepeckers (usually spelled without the "k", but I wanted to draw attention to the appropriateness of that name).

A graphic showing the cone of accelerated winds over the Tehuantepec (from Sarana's Explore Central America).

Generally, for cruising sailors, a "one-foot-on-the-beach" strategy is taken to cross the Gulf, meaning staying within 3-miles of the beach in about 100 feet of water. (Some try to dash straight across; some talk about going 500 miles out to sea, the first being rather dangerous--nowhere to take refuge--the second onerous due to distance.) If the wind starts to blow from the North, the recommendation is to move to within 1/4 to 1/2 mile of the beach, in about 30 feet of water, just outside the breakers (the idea, frankly, terrifies me even more than high winds and steep waves) the idea being the closer a boat is to the beach, the less distance the waves have to build in height (the distance called "fetch") making transiting safer. Adding to the fun are two lagoons with unmarked, shifting shoals, requiring boats to turn into deeper water regardless of what's happening with the wind.

The beach in the Tehuantepec, three miles away.

On top of everything else, because the trip is so long, part of it inevitably has to be done in the dark. Furthermore, if the wind is blowing hard, most everyone is going to head for the beach, adding to the navigational challenge. Radar would become very important in that case.

So, anyway, I thought we would take some time in Marina Chahué to really understand the Tehuantepec and make a good plan for crossing. But with the information from Ashika, the luxury of time somewhat faded. We didn't want to get stuck in Huatulco for a week or more considering the distance we still had to cover to get to Costa Rica in time for Madeline's arrival, but we didn't want to make a hasty decision in the face of an approaching gale and get pasted in some nasty water.

A long way to go from Huatulco to Costa Rica.

I compiled all the weather information I could: GRIB files, NOAA forecasts, amateur forecasts, and confirmed what Lauri and Dois said. George and I talked about it, fully aware that we were schedule-driven, and schedules are the bane of a cruiser's existance. They tend to make cruisers make bad decisions. However, a four-day weather window is a a pretty good deal: the worst winds weren't expected until Friday and we were thinking about leaving on Monday.

This is a GRIB (gridded-binary) file obtained over our single-sideband radio showing the winds predicted for Friday. Each "flag" or "line" on the wind arrows stands for 10 knots of wind. The highest predicted winds are in the 40 knot range (average), i.e., gale force.

Finally, we decided to buddy-boat with Ashika. Originally, we had a 5 a.m. departure but saner minds prevailed and we made that 9 a.m. Ultimately, Lauri and Dois left on time; we followed an hour-and-a-half later.

The winds were brisk out of the SSW. We put up our drifter and main *and* kept motoring, something we've never done before. The sails remained filled and we picked up about a knot of speed.

I slept and when George woke me up it was dark and the wind was even stronger. I had that disorienting feeling of not knowing where we were or what was out there. After an hour the moon came up, red-orange and spooky-looking at first, but finally it cast brighter light over the sea. I kept a nervous eye on the wind direction, about 20 knots in strength, but still out of the south. If it turned and became northerly, we would have a problem.

I saw the lights of a couple of other boats, northbound and closer to the beach than we were. There was no sign of any other sailboats; Ashika was far enough ahead of us to be out of sight.

By the time I woke up after my second off-watch nap, the winds had moderated a little bit and George had us motor-sailing with just the staysail. By mid-morning the winds had abated even more. I needed a break from engine noise, so I hoisted the drifter and main and we were finally just a sailboat.

A photo from our chartplotter showing our curving route through the Gulf. The arrow is pointed to a green flag indicating where we thought the edge of the high-wind cone was.

We made contact with Ashika during the net that evening and learned they were about 15 miles ahead of us. Behind us was Tusitala just getting started on their crossing and having 25 knot southerlies. They asked for our position so they would know about when to expect milder conditions.

The wind grew light Tuesday night, so we decided to keep motoring throughout the night in order to have a daytime arrival in Puerto Chiapas. During his night watch, poor George got the doo-doo scared out of him when my PFD, which I had stored under the dodger, decided to spontaneously inflate.

We reached Puerto Chiapas at 2 p.m. Wednesday afternoon. The swells coming off the Pacific were the biggest I've seen since our gale off of Cape Mendicino in California, though their period was about 15 seconds, making them impressive but not rough. Once inside the breakwaters, the swell disappeared. George called the marina to let them know we had arrived and they gave us directions through the lagoon. I commented to George how much it was like a jungle tour. There were lots of mangroves (interspersed with piers to which large fishing vessels were tied) and unfamiliar birdsong. The tide was low and the smell of rot was at times intense. I was glad George had called for instructions. The marina was tucked so far back in the mangroves it would have been a puzzle to find without guidance. As it was, our charplotter had us blazing a trail over land.

Motoring through the dredged channel to the marina.

Albion's route through the shallows and the mud. "Mangle" is Spanish for mangroves. The charts and photo overlay are obviously out-of-date.

We reached our slip and were greeted by the friendly marina staff, Dois and Lauri who had arrived that morning, and Judy and Paul from Grace whom we had last seen in Barra. After about an hour we were visited by the Port Caption and the Navy. The first was there to clear us in, the second to inspect Albion with a drug-sniffing dog. They were professional and friendly, and I was fascinated watching the dog work, though Nikki was beside herself to see a dog checking out her turf.

Delta peers through a portlight while Nikki eyes her warily.

Puerto Chiapas doesn't seem like a great destination for cruise ships, but there were two huge ones moored there.

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