The Drake Passage and Cape Horn

The only interruption between the extreme southern mountain ranges of the Andes and the tip, Cape Horn, and the Antarctic Peninsula is the body of water known as the Drake Passage (named after Sir Francis Drake, early English sailor-explorer). This turbulent water occurs where the fast flowing Southern Ocean waters are squeezed between the continental landmasses of South America and Antarctica. Since none of the other continents extend south more than 40 degrees, and Cape Horn is 56 degrees south, cyclonic lows can literally chase each other around the world unhindered by landmasses. Lows press south when they find that they cannot pass easily over the extreme height of the southern Andes Mountains. Thus, the Drake Passage is known as one of the roughest sections of ocean in the world. Cyclonic lows of near-hurricane strength travel through the passage roughly every three weeks. Couple that with waves racing from two and sometimes three different directions as a result of the Pacific and Atlantic Oceans converging, and you have the makings for water so rough and dangerous that even the most seasoned captains fear to cross. It is not uncommon for a modern ship without stabilization thrusters to roll up to 40 degrees in huge waves. It is also not uncommon to encounter wind speed changes of 50 to 60 knots and directional changes of 20 to 45 degrees within a short period of a half-hour or so. It is also not uncommon to find the passage almost calm with only an inkling of gentle waves and wind. The Drake is unpredictable!

Two hundred years ago, wooden ships sailed by the wind and navigated by the stars. They had no choice but to round Cape Horn, regardless of the season or the weather conditions. For most navigators rounding the Cape it was treacherous work because they were navigating by stars in the Southern Hemisphere that were mostly unfamiliar to them. The navigation officers could only guess at the weather forecast and hope. Icebergs and thick floe or pack ice were often serious threats particularly at night because they could not easily be seen. Because of primitive navigation instruments, lack of precise charts and limited manoeuvrability of the ships, it was necessary to give the treacherous rocks and reefs of the coast a wide berth. This meant that ships had to spend extended periods of time out to sea without the protection of the coastal terrain. Thus the ships were at the mercy of the waves and wind. The direction of wind was absolutely vital to the direction in which the ship could tack and travel. To sail safely in a constant direction, the wind had to remain strong and steady. Often captains were caught unawares by sudden climatic wind changes or ran into icebergs and suffered terrible consequences as a result. Ships were often blown north on to the Cape Horn reefs with their sails and masts wrecked and beyond repair.

Bob Wallace is an Antarctic ice-ship Captain, master boat craftsman and plays the character of Shackleton in the IMAX film Shackleton’s Antarctic Adventure. Bob is truely a salt of the sea. He’s taken his vessel, the Able-J, down to Antarctica over a dozen times to explore the peninsula region. What drives him to sail the Antarctic waters is ultimately the spirit of adventure, however one of his primary passions is assisting scientific researchers gain access to remote, uncharted islands. In the last 20 years he has assisted many scientific teams explore the peninsula. On one such occasion, he took a research party to the Joubin Islands where they were able to land, and successfully completed the first wildlife study that had ever been done in the area. The waters surrounding these islands had not been surveyed, and Bob was able to navigate using lateral sonar, discovering rocks and ice ahead of the ship as they approached them. As Bob likes to point out, "A depth-sounder that shows you what’s under you - that’s what we call ‘historical’ information."

In addition to assisting scientists in their exploration of Antarctica, Bob has also worked on some research of his own. In the Antarctic Peninsula region, he has begun studying the territorial extents of Chinstrap and Adelie penguins as indicators of climate change.

Bob is a superb storyteller with a tremendous knowledge of the history of exploration in Antarctica. He is a member of the Massachusetts Chapter of the Explorer's Club and is joining Fathom Expeditions Spirit of Shackleton expedition to lecture on exploration, boat building and ice navigation.