Message in a Bottle
Total Page:16
File Type:pdf, Size:1020Kb
Green Wakes Why couldn’t we track our messages? People track boats, dogs, phones and even the location of their keys these days. BY ERIC AND ANGELA SIEGEL TRACKING MODERN MESSAGES in a BOTTLE I N G I S W O U ••••••• R R ••• •• L C •• •• D • • Sail GREEN • • • • • • • • D • • 7 • • • • • • E 1 C 0 2 E M R B E cruisingworld.com riting a message, inserting it into a 38 glass bottle, cork- W ing the end and throwing it overboard is a traditional rite of passage for many off shore sailors. Tossing a message in a bottle is similar to playing the lottery, in that the value is in the dreaming and only rarely in the actual outcome. With a message in a bottle, one can dream of the distant shore it will wash up upon, and who will fi nd the message while beachcombing. november/december 2017 My husband, Eric, sent his fi rst message in a bottle while on a college research program sailing from St. Petersburg, Florida, to the Dry Tortugas, a small island cluster 60 miles west of Key West. Several months later, he was lucky enough to receive a nice letter from an elementary-school the long passage across the has been recovered. But that Angela and Eliana prepare group that found the bottle Atlantic Ocean. hasn’t prevented us from to deploy Drifter E fi ve while participating in a science Several years later, we dreaming about their respec- days out from Cape Verde program on a beach near Fort deployed several messages, tive paths through the seas on the way to Barbados. Lauderdale. The bottle had safely corked in bottles, as we and where they might one day clearly been entrained in the crossed the Pacifi c Ocean on be found. Our passage, on our trusty Loop Current in the Gulf of Rouser, our Tartan 37, during Most recently, we have Westerly 49, Laridae, origi- Mexico, navigated the Straits a two-year voyage originat- introduced our three young nated in Scotland and ended of Florida and exited the ing near Seattle and ending children to the experience of in the Caribbean, with calls in Gulf Stream north of Miami, in New Zealand. So far, not a sending messages in bottles as Spain, Portugal, the Canary making a timely escape before single one of these messages we crossed the Atlantic Ocean. Islands and the Cape Verde ERIC SIEGEL CRW1217_GRN_Message.indd 38 9/25/17 5:06 PM GREEN WAKES islands. This time, however, Writing the messages in the positions: 15°N, 30°W (Drifter order to jump overboard to the messages that our children bottles was a fun group activ- A); 14°N, 32.5°W (Drifter D); clean the speedo, or should we launched were much diff er- ity. Prior to leaving Scotland, 13.5°N, 35°W (Drifter E). The continue to enjoy the fi rst few ent. The innovative concept we had a bon voyage party drifters were deployed in age hours of our grand departure, began when one of our chil- with our children where their order of our children, but it sailing in close company with dren naively asked us why we friends wrote messages for helps that this is also (acci- the 30 other boats around us in didn’t know where our previous inclusion in the bottles. Later, dentally) in alphabetical order. the rally, and live for the next bottles were located. As with having joined Jimmy Cornell’s When we set out the fi rst two weeks without the knot-log most things, each new genera- Barbados 50 rally to cross buoy, the true-wind speed was data? After our recent show- tion has a more contemporary the Atlantic, we invited all of about 25 to 30 knots from the ers and the knowledge that few take on things, even age-old the kids and adults to write northeast to east-northeast. showers were in store over the traditions such as this. Why messages and draw pictures The wind slowly diminished to next few weeks, the fresh, clean couldn’t we track our messages? to include in the bottles. The about 25 knots for the second feeling won out over a salty People track boats, dogs, three bottles were corked drifter, and to around 20 knots swim. We decided to continue phones and even the location on the dock in Mindelo, an when the third drifter on toward Barbados, sailing of their keys these days. island in Cape Verde, and tied was launched. within sight of our fellow rally Our messages keep to securely to the three drifting Trained as a physical boats, but without a work- tradition in some ways, but buoys. The drifters were given oceanographer, Eric was ing log to be able to estimate wildly deviate in others. We letter identifi cations after very excited to sail across the ocean currents. Fortunately, the decided to attach our stan- our kids’ names: Drifter A for Atlantic Ocean and compare drifting GPS buoys were able dard message-carrying bottles to satiate our interest in the to modern drifting buoys that ocean currents, and following transmit their position to a their course across the Atlantic satellite. Now, we all get to Ocean has been fascinating for track their meandering routes the entire family. across the ocean and, with the understanding of surface winds Tracking the Drifter Buoys and ocean currents, make When the drifters were educated guesses of where they deployed, the trade winds will ultimately go. were blowing from the typi- cal direction of northeast to cruisingworld.com Drifter Buoy Technology east-northeast at a speed of Our friends at Marine about 25 knots. For the fi rst 39 Instruments, an innovative fi ve days (and 100 miles of buoy technology company in Spain, drift), the buoys followed our donated the drifting buoys for path so closely that we received the project. The MSi drifter an email from Eric’s father buoys (marineinstruments.es/ asking if we had tied them to tuna-fi shing/buoys-msi-blue) our transom and were towing contain a GPS for positioning, them along. Even though the an Iridium modem for satellite drifters were directly follow- transmission of the position ing our path, the buoys were and a small solar panel to keep not drifting exactly down- the batteries charged. The drift- The Siegels set up a website to track their bottled messages wind. We had been sailing on ers transmit their GPS position (orange, red and yellow lines), and were amazed to see how a starboard tack, with a wind every 12 hours via the Iridium closely the drifters followed their own path (blue line). angle of about 140 degrees. modem. The drifters do not Therefore, the buoys were november/december 2017 have a sea drogue and have Anneka, Drifter D for Dorian our knot-log speed (speed following an angle about 40 very little exposed windage. and Drifter E for Eliana. Each through the water) with our As a result, they drift primarily of our three children deco- GPS speed (speed over ground) with the ocean surface currents rated their bottle and their to try to estimate the ocean- CURRENT found in the top few feet of the assigned drifting buoy and current speed. However, CONVENTION water. This surface layer is added the words “Read Me” in within moments of depart- The standard convention for the same layer that aff ects sail- large letters. ing the dock, we learned that describing winds is “from.” boats with typical drafts from Mindelo’s harbor inspires a An easterly wind is blowing 4 to 8 feet. Current lore of the Drifter Buoy Deployment lot of critters to make them- from the east. The conven- tropical Atlantic Ocean is that We launched the message-fi lled selves at home on the hull, and tion for describing currents is “toward.” A northward the buoys should drift mostly bottles and drifters on days our knot log was fouled with current is moving toward downwind, at an approxi- three, four and fi ve (November new growth. While surfi ng the north. mate speed of half a knot. Our 11-13, 2016) after departing down waves with 35-knot gusts, friends at Nortek Data Services Cape Verde on our 2,100-mile funneling through São Vicente have graciously volunteered to passage to Barbados. The drift- Canal between the islands of degrees to the right (clockwise) host a webpage that plots our ers were deployed with an equal São Vicente and Santo Antão, of the wind direction. This is sailing route and the position spacing of 2.5 degrees of longi- serious soul-searching had to be consistent with how surface and path for the three messages tude (approximately 145 miles done. Should we divert course currents should be oriented tied to the drifting buoys. apart at this latitude) at the to a protected anchorage in with respect to the prevailing CRW1217_GRN_Message.indd 39 9/25/17 5:06 PM of their intended westward TRACK THE DRIFTERS direction due to the Coriolis The position of the three drifting buoys is tracked Scotia, Canada. The SVP buoy uses a large drogue force. The north-northwest in real-time and can be found by clicking on the to control its drift. The sea-anchor type is known drift persisted for another map link on the bottom of the webpage as a “holey sock drogue.” It essentially looks likes 10 days before the typical laridae.ca/2016/11/29/drifter. The blue line shows its name, and is designed to be centered about 50 east-northeast trade winds the path that Laridae sailed between Falmouth in feet below the sea surface.