The Blue View - Finding the Gulf Stream

We are very conservative sailors. We reef down before we need to when we see potentially bad weather approaching or in the evenings when we can't always see a squall coming our way until it is on top of us. Likewise, we use less sail than we did a few years ago - we'd rather trade a few miles of distance each day for a more comfortable ride. We call it 'leisurely sailing' (although in our younger years we undoubtedly called it 'old fart sailing'). A good day for us now is 150 nautical miles, just over an average of six knots.

That said, we are certainly not opposed to going out of our way a bit to find a friendly current or avoiding an adverse one. We had a fast passage from Brisbane to Sydney Australia one year by taking a free ride on the the East Australia Current. Our only 200+ nm day was thanks to the extra 3+ knots that we picked up from the Agulhas Current off South Africa. On the other hand, we tried our best to avoid as much of the Humboldt current as we could, as it was against us for most of our trip down the west coast of South America.

Now as we head up the east coast of the U.S., we are hoping to add 50-75 nm to our daily passages by taking advantage of the mighty Gulf Stream, just as mariners for the past 400 years have done. Its location is fairly constant along the south Florida coast, but the course it follows varies as it travels further north. For the modern day sailor, however, locating the Gulf Stream is much easier than it was even thirty years ago.

A hundred and fifty years ago, mariners would use Maury's Pilot charts and the captain's acquired knowledge to follow the most likely course of the Gulf Stream. By taking periodic sun and star sights using a sextant, the navigator would compare the distance made good to the dead reckoning position and get an idea of how much current was present. In the twentieth century, but before GPSs and satellite imaging, the offshore sailor would head eastward to the 100 fathom depth contour. He would then set a course to follow a few miles east of this contour. (This is the edge of the continental shelf, where the depths quickly drop from a few hundred feet to several thousand feet. (Interestingly, the Agulhas Current follows a similar depth profile off the South African coast.) He might also measure the water temperature to adjust his course, as the temperature of the water in the Gulf Stream is several degrees higher than the surrounding water.

These days, locating the Gulf Stream is quite straightforward. There are daily updates of the thermal satellite images of the Atlantic coastal waters. By going online prior to our departure, I can download the latest images showing the precise location of the Gulf Stream. I use these images to plot a series of waypoints on our chartplotter that will get us to and follow the current. Once we are in the Gulf Stream, we can measure the strength of the current by comparing our 'Speed Over Ground' as measured by our GPS to our 'Speed Through the Water' as measured by the speed transducer on the hull. The difference between the two is the speed of the current.

Technology is wonderful. No doubt, in another thirty years, on-board computers will monitor weather conditions and adjust the sails to maximize our velocity made good, smart radar sets and AISs will monitor other vessels and automatically avoid collisions, and satellite imagery will plan the fastest route. I'll opt for a system that includes a setting that adjusts the ride - where a setting of 1 is the most comfortable and a setting of 10 is the fastest.

Then all I'll be needed for, assuming we are still around and capable of climbing aboard, is to compile the list of repairs to be done at the next exotic port of call.

The Blue View - Watching Out for Hurricanes

We've had a taste of three tropical storms during our sailing days – one in a marina and two at sea. When we were still chartering boats a few decades ago, we learned that the rates were significantly less if we rented a boat during hurricane season. I figured the odds of encountering a hurricane during the 10 days of each season we were chartering were pretty low. The odds caught up with us one year, however, when we took a direct hit from Hurricane Bertha in the British Virgin Islands. We hunkered down in a marina in Virgin Gorda, prepped and secured the boat as best we could, then sat through it. We watched coconuts fly through the air as though fired from a cannon, and had a brief “eye-of-the-storm” party before the second half of the storm assaulted us. It was only a Category 1 hurricane, and was more of an adventure than anything life threatening – especially since it was a chartered boat and not ours.

On Nine of Cups, we got chased down the Tasman Sea off the west coast of New Zealand by a cyclone one year, then got a taste of another cyclone between the Chatham Islands and the east coast New Zealand's north island another year. Neither was a direct hit, but both were certainly unpleasant. Both were out of the normal cyclone belts and weren't predicted until we were en route on passages. The first one caused some rough weather, but veered off before catching us. We caught the edge of the second one and suffered a knockdown and considerable damage from it.

We'd just as soon not have any more encounters with tropical storms, hurricanes or cyclones, especially at sea, and now, as we are heading north up the east coast of the U.S., we're paying close attention to what's brewing out there. Hurricane season didn't officially start until June 1, but Tropical Storm Bonnie beat the gun, hitting the Carolinas on May 29th. We had planned to depart St. Augustine right about then, but it wasn't a difficult decision to postpone our passage until she passed by.

It should be a 4-5 day passage to the Chesapeake, and if another tropical storm develops while we're en route, we should have enough notice to seek shelter. The forecasters usually provide that much warning these days, and you can be sure we'll be downloading weather advisories daily.

The Blue View - When It All Goes Wrong

Most of our passage from Puerto Rico to St. Augustine was idyllic – a nice broad reach with 15-20 knots of wind, a kindly following sea, warm sunny weather, a 0.5 to 2 knot favorable current, and a full moon to sail by at night. The prop shaft generator and solar panels were producing more power than we needed and nothing major had broken. We couldn't have asked for a more perfect passage – at least for the first six days.

Marcie's blog yesterday talked about how things can quickly change. And when things start going wrong, usually it happens just as the wind picks up, at night and in the middle of the shipping channels – and usually the problems come in multiples. Our first problem was a transmission leak. Without our engine, we could have beat our way to the St. Augustine inlet, but with wind on the nose and the gulf stream current pushing us NE, this would have taken awhile. Then once we arrived, we would have needed a tow to make our way through the narrow, dog-legged inlet – an expensive option. A much better option would be to figure out the transmission problem.

One possibility was the heat exchanger. It is about the size of a half empty roll of paper towels. Sea water is passed through the heat exchanger, and the transmission oil is cooled by pumping it through a coil of tubing that is immersed in the water. Over time, the inner tubing deteriorates and eventually begins leaking. Since the oil is under pressure, it will leak out into the sea water. Usually, once the engine is shut down, sea water will leak back into the tubing, filling the transmission. I wasn't getting seawater into the transmission, but I thought the heat exchanger might still be the culprit. I try to change the heat exchangers every three years, but this one had been in place more than four years and was overdue.

I had a spare, and it took only a few minutes to dig it out. To remove and replace the old one, I had to first remove a shelf in the aft part of the engine room that holds a bin of miscellaneous engine spares as well as my compressor. The rest of the R & R process took about an hour, and all together, the whole thing took maybe 90 minutes for the entire procedure. It went well and without a hitch – always a bad sign.

We topped up the transmission oil and started up the engine. I didn't see anything leaking, so we motored for an hour, then I checked the oil level again. Yikes! It was down another quart. We have three hydraulic hoses connected to the transmission – two that go to the heat exchanger and one that operates the prop shaft brake. With the shelf out I had a better view of the hoses, and I saw a small collection of oil on the hose for the prop brake. I removed it, and sure enough, there was a crack in the underside of one of the fittings.

We could do without the hose if I could figure out a way to plug the hole it was screwed into on the transmission. I rooted around in my various parts bins and finally found a brass hose barb adapter with the right size male thread. Using a bolt, nut and copious amounts of Permatex Gasket Maker (the type impervious to transmission and engine oil), I made a plug for the hole that would withstand the pressure. I screwed it into place, topped up the oil, and we motored for another hour. When I checked the oil level again, the good news was that the oil level seemed to be holding. The bad news was that the engine room was awash in seawater. While I was trying to figure out where it was coming from, the high water bilge alarm went off.

There is an old adage that there is no better bilge pump than a panicked sailor with a bucket. While we weren't quite at the panic level, it was obvious we needed to handle the problem. I closed all the seacocks that could possibly be feeding water into the engine room then we turned on both electric bilge pumps, Marcie began pumping the manual bilge pump, and I worked at bailing out the engine room. Even so, we were barely keeping up with the water ingress. Where the hell was all that water coming from?

Then I spotted the culprit. The prop shaft seal, which is located well aft of the engine room, has a vent hose that should be led up above the water line. I had routed it to the top of the engine room and secured it in place with cable ties. Apparently, when I removed the shelf, I inadvertently pulled it loose from the cable ties. It stayed in place for awhile, but the vibration from the engine caused it to slide down and the end eventually came to rest on the engine room floor – well below the waterline. It was a quick fix to put it back where it belonged, and this time I made sure it could never come loose again.

It took another half hour to pump out all the water and clear the engine room. After checking everything one last time, we were on our way. We checked the transmission oil every hour for several hours, and it was no longer losing oil.

What I took away from all this was that while it was nice to be able to find and repair the transmission leak problem, I am most embarrassed that I didn't properly secure the vent line, causing an emergency situation.

Looking at the bright side, we did get to test the high water bilge alarm and all three bilge pumps, which, happily, all worked.