Friday, November 17, 2017

Farewell, Charleston

I am typing in the Atlantic Ocean, about 15nm off the coast of Cumberland Island, Georgia. We've been out of Internet coverage since about 7:30pm last night, off the coast of South Carolina outside of Port Royal and Beaufort. I spent part of my watch last night editing photos and get them ready for upload here, but typing on watch in the dark is more difficult for me.

Corner of King&Queen, near where we had one of our final meals in town, at 82 Queen.

We ended up spending over a full week in the anchorage across from the City Marina. Our commitment had been to remain until Sunday morning's service at the Unitarian Church of Charleston, where Louise had joined the choir in my absence. Short on tenors, she really wanted to help them out Sunday. I enjoyed the service, and hearing her sing, and we made good use of the five extra days to wrap up our visit in Charleston.

That meant we could have left Charleston on Monday, except the weather on the Atlantic has not been conducive to it. For Vector, even going to Savannah means an outside passage, due to a couple of shallow stretches on the inside route. With a seven-foot tide swing here, we can navigate them close to high tide, but that requires a lot of fiddly timing that makes what ought to be a two-day trip into three or four days. We try to avoid it if we can.

So we remained in our snug anchorage until the weather settled. When it did, we got a very nice window that was good all the way to Florida, and we seized the opportunity, which is how this morning finds us off the coast of southern Georgia, on our way to Jacksonville.

When last I posted here, we were still at the dock, preparing to leave. We very carefully timed our departure for slack tide Tuesday morning, when we awoke to a cruise ship tied up to the dock, the brand new American Constellation. We filled the water tank, took the last of the trash and recycling off the boat, singled up lines, and disconnected the power cord, all per our usual pre-departure checklist.

The American Constellation, the newest and largest ship plying the ICW for American Cruises.

Things went off the rails, however, when I finished my startup checklist and started the main engine. Louise normally stands on the aft deck during or immediately after start-up to make sure we have water flow from the exhaust, and this morning she immediately reported back that we had no flow. This is an emergency of the first order and I very quickly shut back down.

For the unfamiliar, a marine wet exhaust system relies on seawater being pumped into the hot exhaust a short distance downstream of the engine, so that the exhaust can continue on its way through the rest of the boat in hoses rather than pipes. Cooling the exhaust this way makes for a cooler engine room, a cooler boat, a safer exhaust system, and less noise and smoke at the stern. The cooling water first cools the engine itself, by way of a heat exchanger, and is pumped from the sea by a rubber-impeller engine-driven pump.

No water from the exhaust meant that neither the engine nor the exhaust system was being cooled. A cold engine can run for a long time that way, maybe several minutes. But the hot exhaust will quickly burn through the hose system or fiberglass muffler that carries it out of the boat. This can start a fire and/or sink the boat, and to prevent just such a disaster we have a high-temperature alarm on the exhaust system, which sounds in the pilothouse if the hose gets over 170°F.

One of our final sunsets from our aft deck.

Remembering that we'd done quite a bit of work in our four months at the dock, including cleaning out the sea strainers, and that we had a diver clean the sea chest literally the day before departure, filling it and all the through-hulls and pipes with compressed air, we started the engine back up and ran it a full minute to see if it was just air entrapment and loss of prime. Still no flow.

Reluctantly, I called the marina on the radio to let them know we could not leave the dock (the marina has been full every night, turning away over a hundred boats last month, and we knew they needed the slip), and that it would take me at least two hours to diagnose and repair the problem. And to be prepared for the possibility that we might be stuck overnight, if not longer.

Fortunately, it turned out to be nothing more than the "usual suspect": a shredded impeller in the seawater pump. These impellers don't like sitting in one spot for long periods (we did run the engine monthly), and a big hit of air trapped in the line from the diver meant it likely ran dry for a second or two. The pump has to come off the engine to replace the impeller, and all told it's about a two hour job. I have an entire spare pump which can knock a half hour or so off that, in case I need to do this at sea, but tied to the dock it made sense just to finish the job.

Vector at anchor, as seen from the Megadock.

By the time we were done and confident the pump was working and there were no water or engine oil leaks, we had a wicked current against our stern and we were still coming up to max ebb. We called the marina back and pleaded for a 2pm departure (well past the noon check-in for new arrivals), which would at least cut the current in half, down to a manageable knot or so. They agreed and we settled in for another couple of hours.

As the marina has been quite full these last few weeks during the annual southbound migration, so has the anchorage. We looped all the way through it once before settling on a spot near the southeast end, still within reach of the marina WiFi, and about the closest we could get to the dinghy dock, which is still a long slog around the back of the marina.

This anchorage is notorious for fouled anchors; numerous wrecks litter the bottom, along with remnants of old moorings, lost anchors and chains, and other detritus. We thought briefly about deploying a trip line with a marker buoy, but that has its own liabilities in an anchorage like this. Instead we just picked a spot closer to the channel (and outside the designated no-light-or-ball required anchorage) in 30' of water and hoped for the best.

We got a good set and put out 120' of chain, a 4:1 scope, the least we'll do in this kind of current. Other than a couple of inexperienced sailors who anchored too close to our swing circle and subsequently had to move, we had no issues. The current and wind had us mostly "fill in" our anchor circle over the course of nine days, reminding me of those computer-graded tests you had to take with a #2 pencil.

Filling in the circle.

I used the extra nine days productively to get a few projects done. I got under the helm and installed the interval delay timer for the wipers and a knob/switch to adjust the interval; the single switch activates all three wipers. While I had part of the gear out of the under-helm cabinets for access, I also did a major clean-up in there, properly securing the numerous spare electronic items that have accumulated there. My "man cave" is once again easily accessible.

New interval wiper control, alongside three existing wiper switches.

Many of the days at anchor were extremely cold, and we had to run the reverse-cycle heaters. The salon unit kept tripping its breaker, so I also ended up cleaning the sea strainer once again (yuck) as well as back-flushing the unit's heat exchanger. Sadly, that did not fix the issue, and we'll need to have a refrigeration technician look at it. We just used one of our little electric fan heaters in the salon in the interim.

Sailboats everywhere leading to the start of the regatta. The ones with sails down are anchored.

The weekend found us in the middle of a sailing regatta, with the starting line just upriver from us, near the bridge. Several classes of boats had separate starts, all started by firing the yacht club cannon. We knew about the regatta, and had met the cannoneer, because we had a beer at the Yacht Club on Friday evening. The entire anchorage was a swirling maelstrom of racing yachts, jockeying into position for the start, and then some cutting through the anchorage in the course of the race. Several passed Vector close aboard.

A race boat passes us close aboard.

Shortly after leaving the dock we got another couple of packages in the mail. We intended to dinghy ashore to get them, so we were surprised when one of the dockhands showed up in the pumpout boat (Bow Movement, sister boat to The Grateful Head) to deliver them to us in the anchorage. I have to give the City Marina an A+ for customer service. One of those packages contained my new silver/silver-chloride reference electrode.

The diving service that cleaned our hull in Charleston (twice, which in hindsight was not enough) reported that they thought our anodes were not doing their job, as indicated by the amount of growth they had accumulated. They tried very hard to convince me to have them replace our fairly new aluminum-alloy anodes with zinc ones. This made little sense to me; aluminum-alloy anodes are more effective than zinc, and tech divers are not necessarily experts on galvanic protection.

The way to know for sure is to measure hull potential, which requires a voltmeter and a "reference electrode" suspended in the salt water outside the boat. We had this test performed on our first yard visit over four years ago, since we had done lots of electrical work and changed the anodes. But we have not been tested since changing over to aluminum alloy anodes during our haulout last year at Snead Island.

With my shiny new reference electrode in hand, I was able to make several measurements of hull potential at various points around the boat, with the electrode close aboard and also with it perhaps 15' from the boat. I consistently got a reading of -.907v at all locations, right in the middle of the recommended range for steel boats. I'm not sure why the anodes are accumulating growth, but I'm not going to worry about it with these readings.

The other delivery was our mail from our box in Green Cove Springs. Ironically we will be nearly there in another day or so, but we had items in the mail that we needed. I was happy to find in there a nice gift from Lila, whom we met in Fort Lauderdale back in July. Lila decided she wanted to raise money for hurricane relief in Puerto Rico, and she made lovely little pennant banners as thank-you gifts to those who donated.

Of course we made a donation, and if you will permit me a brief digression, Lila's project still brings a tear to my eye when I think about it in the context of our own disaster relief work. As I have written here before, a substantial portion of donated funds for disaster relief go to the logistics of transporting, housing, feeding, and caring for relief workers, most of whom are themselves volunteers.

Our homemade banner proudly on display.

When we are on relief assignment, we're issued debit cards which we use for transportation, meals, and other incidental expenses. There's a daily maximum allowed, with suggested amounts for meals and the like, but we hope to spend less than the maximum if possible. For example, when I was in St. Thomas, most of my meals were provided by FEMA on board the ship where I was housed; I spent almost none of my meal allowance during my deployment, with the exception being while I was en route.

Anyone who has ever worked for me on a deployment has heard my stewardship lecture. I remind everyone that the funds on that debit card come from people just like Lila, a little girl who just wanted to help disaster victims rather than have a new toy for herself. They don't come from the government, or some magic pot, or even the amorphous "budget," and spending them indiscriminately disrespects the donors like Lila. While Lila raised funds for a different agency, it's all of a piece, and I am so thankful there are children like Lila, and parents who instill the values of caring for others in this way.

While we were at the dock for a full four months, it took being at anchor to finally get us out to two things we've been trying to do for quite a while. The first was dinner with new friends Bill and Ann, who live on a nice motor yacht at the marina. Ann and Bill work different shifts, and so they only ever get to eat dinner together one or two nights a week. We met them months ago but it took us this long to find a time that worked for everyone.

The other was a city tour by bus. Charleston is chock-full of walking tours (the city is really ripe for them), but Louise generally can't do a walking tour. And there are spendy horse-drawn carriage tours, but naturally they can only cover a few blocks; you need to take four of them to take everything in, and the tour routes are assigned to carriages randomly at the last minute, so it's a challenge to get four different ones.

Our busy anchorage. I counted 28 anchored boats one day. Two of these boats are stuck with fouled anchors.

On our very last day in town we had a nice brunch at Eli's Table and then made our way to the visitor center to board a small bus for a 90-minute city tour. The driver/guide was quite the character, and even having been in the city for four months, we saw and learned about several things previously unknown to us.

That morning the outside weather forecast was still questionable, but by Wednesday evening it was clear we'd have good weather all the way to Florida overnight on Thursday. We made our preparations to leave on the morning ebb, which would mean a high-current tie-up at the Megadock to board the scooters. But I had a great deal of apprehension about weighing anchor.

That's because two boats just upriver of us in the anchorage had tried to depart in the last couple of stays, but were stuck fast. A diver was due to arrive before slack tide in the morning to see if he could un-foul them. We weighed anchor just as the diver was arriving; fortunately, it came up mostly clean.

Weighing anchor. Cruise ship American Constellation in the background. The sailing cat just to the left was stuck, his anchor fouled.

To be fair, one of those boats dropped its hook almost right on top of the hazard marker in the online database warning everyone the area was foul. He paid the price -- his anchor dropped deep inside a wreck and the best the diver could do was cut his chain close to the wreck. The other boat dropped a hundred feet away and was fouled on some chain; he was able to get off with only a lightening of his wallet. We ended up going out the inlet with him, a large sailing cat with a mast too tall for the ICW.

We were able to tie up briefly on the inside of the Megadock, where we again found American Constellation, back from its ten-day cruise (its smaller cousin, Independence, made an overnight visit earlier in the week). That gave us a port-side tie, bow-in to the current, and we loaded the scooters without drama. I had to jury-rig some lifting tackle for my new scooter, but otherwise it hoisted and stowed on the deck without issue. We had some concerns because the tail trunk is not detachable as it was on Chip, which we generally hoisted trunk-less.

The Battery, Ravenel Bridge, and USS Yorktown.

We were at the dock just 45 minutes and then headed for the inlet on a gorgeous fall day. Views of The Battery with the Ravenel Bridge and the USS Yorktown were spectacular, and of Fort Sumter nearly so except for the sun behind behind it.

Fort Sumter, site of the shot heard 'round the world, with the park ferry docked.

We've had a great passage, with calm seas and clear skies, and a nice counter-current push from a Gulf Stream eddy. This latter has caused us to have an ETA to the Jacksonville jetties right at max ebb; I keep dropping the throttle back to try to arrive with a bit less current against us.

Update: As feared, we arrived right at max ebb. With the ship channel 50' deep, the surface turbulence was manageable and we made the inlet and pressed upriver a mile and a half to the first safe spot to drop the hook. We're anchored on a "lunch hook" until the tide changes before making our way upriver to our anchorage for the night.


  1. Sean -

    Re. Lila: I still remember when we were in Alabama in 2011 a young girl bringing in her piggy bank with maybe $15 of change to hand over to the DRO. Made [at least] my eyes well up, and hopefully such lessons are taken to heart by many.

    1. Thank you for sharing that memory, John.

  2. Why couldn't the seawater pump use a stainless steel impeller?

    1. I am an electrical engineer and computer scientist, so hydraulics and pump design are something of a black art to me. That said, I know a few things.

      Seawater pumps on small marine engines are universally a type known as a Flexible Impeller Pump. As the name implies, the pump relies on a flexible impeller, whose vanes are alternately flexed and unflexed by a distortion of the otherwise circular pump chamber called a cam. This is what causes the pumping action. A flexible impeller pump is a close cousin of the vane pump, and is a positive-displacement type pump.

      Rotary pumps with metal impellers are generally of a variety known as centrifugal pumps. Centrifugal pumps are not positive-displacement; they rely on imparting energy to the fluid to cause flow. There are lots of reasons why centrifugal pumps are a poor choice for this application, including variable input speed, variable back-pressure, requirement for self-priming, and ability to handle solids (debris) in the fluid up to a certain size. By contrast, the seawater pump for our air conditioning is a centrifugal pump (bronze impeller), and the coolant-circulating pump on the engine, which I rebuilt this year, is also centrifugal.

      Flexible impeller pumps are a cost-effective positive-displacement rotary pump for the application, but the impeller is a wear item and should be changed on a schedule (the impeller that failed was not yet due for replacement).


Share your comments on this post! We currently allow anyone to comment without registering. If you choose to use the "anonymous" option, please add your name or nickname to the bottom of your comment, within the main comment box. Getting feedback signed simply "anonymous" is kind of like having strangers shout things at us on the street: a bit disconcerting. Thanks!