Prince of Tides

Yesterday I moved the boat from Ford to Thunderbolt, the area where the Intracoastal Waterway passes closest to Savannah. It takes approximately 40 minutes to drive my car from home to Thunderbolt, but in my boat it is a winding 33 nautical mile passage that takes nearly five hours. I go part way down the Ogeechee River to a spot where it connects to the Grove River. The Grove then merges into the Little Ogeechee River which empties out into Ossabaw Sound where I join the Intracoastal Waterway north to Thunderbolt.

I am normally required by my draft to depart our marina at Ford close to high tide and I benefit from the tidal current rushing out that adds to my usual 7.5-knot pace. This week, because of the full moon close to the earth, our tides have been extreme. The range between high and low tide measured at Fort McAllister is normally between six and seven feet. But today for example, there is a low tide this afternoon of negative one foot followed by a high tide tonight of 8.7 feet -- a range of 9.7 feet. (Tides are expressed relative to "Mean Lower Low Water", which is the average height of the lowest tide recorded at a tide station each day during a standardized 19-year recording period.) All of this water dropping nearly 10 feet over about six hours creates very strong currents, and at one point yesterday I was cruising at nearly 11 knots downstream. It was a fun ride and shaved roughly 30 minutes off of my trip. 

The reason for this trip is a story about problems in the "supply chain" for many items right now. Last week, when taking my boat to Thunderbolt for some minor electronics issues, the depth finder started acting up. It would rapidly jump around showing random depths that had nothing to do with reality. After some diagnosis by Mike King of Coastal Marine Electronics and a discussion with Garmin, it was determined that the transducer that fits through the hull of the boat was faulty. This is a fancy and rather expensive forward-looking sonar that shows the depth out in front of the boat to help avoid running aground. Mike called to tell me the good news was that that the transducer is under warranty and the bad news was that Garmin had none in stock and didn't know when they would be available. In fact, there was some indication it might be next year before I could get it replaced. 

I needed an alternative. It is pretty treacherous to operate in waters in this area without any indication of water depth. So Mike came up with a solution. I have an additional transducer that is a simple paddlewheel to show speed through the water. We could replace it with a not-too-expensive "tri-mode" transducer that would show depth, speed, and water temperature. The replacement was supposed to fit into the existing sleeve through the hull, but of course it didn't. So we scheduled to have the boat hauled out this week to replace the sleeve and install the back-up transducer.

Meanwhile, after all of this messing about, the replacement Garmin transducer that could have taken a year actually arrived at my house last Friday. So I brought the boat back to Thunderbolt yesterday to have it hauled out to both replace the Garmin and go ahead and put in the other we ordered as a back-up.

The haul out was scheduled for today, but when I arrived at Thunderbolt yesterday I learned that the lift used to haul boats had a flat tire. These are serious tires for a lift that picks up boats weighing up to 150,000 pounds. The tire is being repaired today but I didn't want the boat hauled out Friday only to sit in the hot sun without air conditioning until Tuesday after the holiday weekend. So the schedule now is to haul it Tuesday and put it back in the water Wednesday. I should be bringing it back home next Thursday. Sigh...

Long story, but this is often how things work with boats. We will eventually have everything in order.

Home Again

The boat is safely back at The Ford Plantation. I had considered taking the ocean route home yesterday because of construction at the Causton Bluff Bridge on the Intracoastal Waterway, but it turned out to not be necessary. I called the bridge tender early in the morning and was told it would be open to boat traffic all day. Besides, winds in the ocean were 15 to 20 knots from the east, blowing against the outgoing tide from the Savannah River, meaning it would be a bumpy ride.

I departed Harbourtown Marina at 9:15 as I had currents to fight, and I wanted to get through an area called Field's Cut before the low tide made it impassable for my six-foot draft boat. As a result, I arrived at Causton Bluff Bridge at around 11:30 am when the tide was nearly low, giving me a bridge clearance of 30 feet so that no opening was necessary. By noon I was in Thunderbolt and by 1 pm I was passing Isle of Hope. I was way ahead of schedule as high enough tide to re-enter Ford's marina would not be until near 7 pm. So I idled and dawdled most of the day, drifting in wide spots while I did little projects on the boat. As it turned out, I still arrived at the Ford marina by 6:15. It was a high tide day and I had no trouble at all getting back into the marina.

There are numerous small projects with the boat, so it will be nice having it a block away for the next month or so. I'll be fiddling around on the boat and Mike Lamson's crew will be finishing some waxing and varnish touch up. I've also got a checklist of items needed for the Bahamas such as charts and guidebooks. Our overall game plan is still to depart south right after Christmas and on to the Bahamas from south Florida. 

Church Creek

 Last night was our first opportunity to spend a night anchored out 
on Division Belle. We are about 20 miles south of Charleston in a beautiful anchorage called "Church Creek". The Waterway Guide says that the name derived from the practice of going to church on the flood tide and returning home on the ebb. The tidal currents here are certainly strong enough to require travel to be carefully timed.

The area we traversed yesterday and our anchorage are stunningly beautiful, and match every description of the marshes ever written. It is hard to capture in a photograph, but the vast grasses are greening for summer close to the water and still a delightful straw color behind. The currents and many shallow areas of the Intracoastal Waterway made some of the going very tough yesterday. We departed Beaufort at slack tide around 

7:30 am, and had the current with us much of the day. But at one point approaching low tide we were literally touching bottom in the middle of the channel, meaning depths at low tide were right at six feet.

We stopped here at 1:45 pm yesterday. We could have made it to Charleston, but our slip is reserved for the month of June begining today, and we also wanted to be able to arrive at the Charleston Maritime Center at slack tide this afternoon, to make docking easiest. 

A cold front passed through yesterday, bringing late afternoon severe storms that passed north of us and caused some damage in Charleston, and late evening huge storms that fortunately passed to our south. The storms and strong current led to a fitful night of sleep, checking the holding power of a new anchor and watching the location of strong storms.

We enjoyed a fine dinner on the aft deck prepared by the Lovely Laura Lee. We will take our time this morning departing to arrive in Charleston just after lunch time. This is pretty much what it is all about.


Update: We departed Church Creek at 10 am and arrived safely at The Charleston Maritime Center at 1:45 pm. While the marina here is exposed to wind and wakes, we are tucked into the best spot it has, and the only one that will accommodate our boat. We will get our sea legs quickly and be prepared to rock and roll for most of a month.

Home at The Ford Plantation

After a long journey, and many repairs in many boatyards, Division Belle is finally docked just a block from our home at The Ford Plantation. We left Hilton Head just after noon today, timed to arrive at Ford close to high tide this evening. Unfortunately, that meant a departure near low tide at Hilton Head. So, rather than risk shallow water at low tide in the Intracoastal Waterway, we went out the Calibogue Sound channel at the south end of Hilton Head and joined the Savannah ship channel to come up the Savannah River and join the waterway later in the day. While it was a rough day out in the ocean, we only had a mild chop going out a couple of miles and back inland via the Savannah ship channel. Our timing worked perfectly, and we arrived at Ford at 8 pm. High tide here was at approximately 8:30, so we had good deep water and the current behind us all the way home.

The trip covered 55 nautical miles which took eight hours, at an average of about 6.875 knots. It's a slow boat, but an extremely comfortable one. It was a great weekend and a great day, but we are very, very tired tonight. Next steps are to get the boat cleaned up after seven weeks in a boatyard, get the varnish redone, and make plans to start enjoying it this summer.

A word about tides, boat draft, and boat speed is in order here. The difference between high and low tide in this area is normally about six feet. Our boat has a six-foot draft. The tide not only affects where we can go at certain times, but also what kinds of currents will be helping or hurting our progress. With the current behind us, our eight-knot boat sometimes travels at up to 10 or 11 knots. We planned for today working backwards from a high tide at Ford at around 8:30 pm this evening. This meant we wanted to start coming upriver on the Little Ogeechee at around 6-ish, with the tide helping our progress and giving us plenty of deep water through the sometimes treacherously shallow low country waterways. This schedule dictated leaving Harbour Town Marina at around noon, at dead low tide. Given that, it made little sense to start out immediately joining the ICW through a shallow area named "Field's Cut" at low tide. Thus, we headed out to sea from the south end of Hilton Head, turned up the usually 50-foot-deep ship channel with the current behind us, and rejoined the waterway at around 3 pm, or mid-tide. The plan worked beautifully, and we arrived on schedule and unscathed by shallow waters and opposing currents.

It is good to be home. As with all boats, there is always much work to be done. But what could be more fun?

Sea Level

A few weeks ago, I went to check on my boat at the Hinckley Marine boatyard in Thunderbolt, just east of Savannah. When I arrived, the entry road to the yard was under water. All of the employee cars were parked along the road a few hundred yards from the entrance, and one employee was directing traffic. He told me the tide had gone down already and that I could probably get through and find a dry parking spot, but getting to the dock and my boat might be a challenge. He also recommended a quick car wash that afternoon to get the salt off.

I tentatively made my way in and found all of the employees wearing tall rubber boots and sloshing around the soaked boatyard. I did manage to park in a dry spot and made my way along a narrow wall to get to the docks. While we all know that sea levels are rising, the experience led me to some reading on the subject. This is not a discussion of the causes of climate change, nor is it political. I simply wanted to find out what is happening right here where I live.

There are tremendous tides in our area, and on the day of this experience, they were much higher than average. In Thunderbolt, the high tide that day, February 20, was 9.8 feet while the low tide was -2.1 feet, a big day to be sure. But the measurement of tides is in relation to mean sea level, a number that is constantly rising. The tide gauge at Fort Pulaski is the only official measurement in the state. It was commissioned in 1935 and, since that time, the sea level has risen more than nine inches, a rate of more than a foot every hundred years. And the rate of rise is increasing. The low projections show a sea level rise of two feet by the end of this century while the most extreme show a rise of more than 10 feet in the same period. Almost all of the increase is attributable to the water rising rather than land sinking.

Someone asked me recently why the sea level would rise when glaciers melt that are already in the sea. It doesn't. Sea level rise is caused by runoff from the melting of glaciers that are on land, and by the expansion of sea water as its temperature increases. There are conflicting estimates of how much is caused by each of these factors, but there seems to be a developing consensus that thermal expansion of sea water will play the larger role long term.

Around here, there are signs everywhere of the issues that sea level increase is already causing. More and more frequently, U.S. Highway 80 to Tybee Island has to be closed as it is under water. Low areas along the Thunderbolt area are also routinely disrupted. A portion of President Street in Savannah is being elevated five to eight feet to prevent flooding.

Projecting the exact time that any area of the country succumbs to what is called "chronic inundation" is extremely difficult, as it involves estimating how trends change in the future. But we do know now that Savannah, along with Miami and New Orleans are high on the list of cities that will be affected the most quickly. For a more detailed study by the Union of Concerned Scientists pointing this out, see "When Rising Seas Hit Home". An interesting exercise is an interactive map published online by NOAA where you can zoom into an area of interest and slide the sea level up as much as 10 feet above its current level. For our area of the world, it looks pretty scary even to see the effect of a one or two foot rise.

Work has progressed slowly on the few projects for the boat. I hope to have it out of the boatyard this week or next.