The Dangerous Archipelago

After our epic 18-day crossing from the Galapagos to the Marquesas we both felt it would be awhile until we did night passages again, but here we are departing the security (and friends) in Hiva Oa for the 580-mile passage to Tahanea in the Tuamotus Archipelago. Our friends Roger and Sasha on Edenbal had motored over to say goodbye (do Aussies have an equivalent G'bye to G’day?) who dropped off a stalk of bananas for our voyage. As usual it was hard to say goodbye to so many good friends in Hiva Oa but we did need to travel onward.

Luckily Boxing Kangaroo was just ahead of us for the first two days and the sailing was great in 12 to 14 knot easterlies allowing us to broad reach most of the way. We lost touch with Boxing Kangaroo on day 3 and continued on in ideal sailing conditions.

Here is a view of Tahanea from about five miles out.

As usual we had a little trepidation about sailing to the Tuamotus. It’s and archipelago made up of 78 coral atolls, all just a few feet about sea level (with the exception of a few coconut palms). They are visible only within five to eight miles away and don’t even show up on radar that well. Add to this the treacherous currents between the islands and in the passes and the area has well earned its moniker The Dangerous Archipelago among sailors. Modern GPS helps, but even on our up-to-date charts most of the atoll’s lagoons are uncharted and filled chock-a-block with coral heads or “bommies” in Australian speak. These lurk just below the surface and are difficult to spot in cloudy conditions, late in the afternoon, or when you are traveling towards the sun. In the old days most sailors simply avoided the atolls and sailed the long way around the Tuamotus.

Another problem with the Tuamotus are the passes. Each atoll has from zero to four “passes,” essentially an opening in the encircling coral reef deep enough for a boat to pass through. To make things more interesting, the millions of gallons of water in the lagoon needs to exit and enter the pass three to four times a day with the tides. Most passes can only be entered only during a brief (up to 5 minutes) of slack water, and trying to determine when this slack water period is a task for an MIT mathematical who is married to  an oceanographer.

A German cruiser made a bold attempt to predict the tidal flows with a complicated Excel spreadsheet appropriately named “The Guesstimator.”  It was fields for the time offset of the atoll from Rangiroa (the nearest NOAA tidal station), the direction the pass faces, the number of days the wind has been blowing from a south or westerly direction (fills the lagoon with more water), and a factor for extra wide or deep passes. Now you know why it’s called the Guesstimator. To make things even more complicated the last time the Guesstimator was updated with the current year's tides was 2011, and since then NOAA changed the format it published it’s tide in, you can’t just plug the 2015 tides into the spreadsheet.

Imagine trying to negotiate a pass or navigate through the coral heads during a squall like this.

Just trying to choose which atolls to visit is a daunting task. After listening to a fellow Magellan Net boat on the morning net we decided to sail to Tahanea, which he described as having a pass you could drive an aircraft carrier through. An extra wide pass gives a lot more wiggle room with calculating the slack water time. I had just figured out how to input the 2015 NOAA tides into the spreadsheet when we approached Tahanea’s Middle Pass (and I’m no math whiz). My calculations showed 1:30 pm as the magic moment to run the pass, but when we got there we saw a heavy current line to the right of the pass. We waited outside and watched the current through powerful binoculars trying to make a decision to go for it (remember we’d just had four nights with little sleep). We finally decided the boat could handle the incoming tide (if it’s outgoing and there is an incoming wind you can get standing waves six- to eight-feet high. We girded for the worse and were surprised by a fairly easy, yet brisk, entrance to the lagoon. Once inside Meryl was up on the bow with a walkie talkie to relay steering directions back to me at the helm if she saw a coral head pop up. We followed some existing waypoints from the s/v Soggy Paws website that were spot on and directed us to a nice anchorage just northeast of the pass entrance.

Now, here is when it gets tricky. Just about everywhere there are coral heads lurking just below the surface. Just about anywhere you drop your anchor the chain will 1) rub up against a coral head, 2) get caught in a coral head, or 3) wrap around the base of a coral head.  The technique de jour is to let out about 1.5x of your anchoring depth in chain, then attach a fender or float to the chain with a short length of rope, then repeat at 1x that distance. For us we had floats at 60 and 90 ft. from our anchor. This allows about 50 feet of anchor to lay on the bottom (hopefully not wrapped around anything) with the rest of the chain suspended above the coral heads but with still enough of a catenary force to keep the boat anchored. The first time we did this the chain got hung up on a coral head. I had to snorkel over and try to reposition the line, which meant I tried to pull the 60 feet of chain up hand over hand, only to discover I was now 20 feet deep in the water and running our of breath. On to plan two. I had Meryl motor the boat up and use it’s brute force to move the chain a bit to the right. Once we got all set up right it worked pretty well. Oh, did I mention that sharks kept swimming by while we were doing all of this? I’m sure I looked like dinner to one or two of them.

To add to the ignominy of the situation, once we got anchored we noticed the two catamarans just to the north of us were non other than Twiga and Cinderella. If you’ve faithfully read the blog you’ll now Twiga is the boat we went through the Panama Canal with and Cinderella is their friends.  Long story short is they are both Austrian “naturalists” meaning we saw lots of naked bodies for the next several days. Luckily the next further boat was our friends Paul and Sundra on Arbutus who we had first meet in Cartagena and later at Hana Noe Moa in the Marquesas. Paul’s French mother was visiting for a month so we had a great opportunity to get to know them better during our stay on Tahanea.

Meryl had received a great recipe for Jamaican Rum Banana Bread from our friend Janet on Truant 3 and with the stalk of bananas Edenbal all ripening, it was time for some banana bread. The results were excellent and we shared part of the loaf with Arbutus during a nice lunch visit with them.

Since this was our first night in the Tuamotous we went to bed with images of huge sharks circling under the boat and our anchor chain wrapped in a macramé design amongst the coral heads. Sweet dreams!