Rabu, 09 Maret 2016

To plan arrival times from overnights so as to coordinate with tides, marinas being open and daylight, one has to assume a speed. Divide the distance in nautical miles by speed in knots and you get hours. Several questions in the Coast Guard Captains licence exam involve this fact and an assumed constant speed, which power boaters can more or less maintain. For overnight passages, we assume ILENE will make an average speed of 6.5 knots. We left at 9:30 am with a plan to arrive in mid morning the next day.

But sailboats have only moderate control over their speed, which is largely wind dependent. And it takes a minute or two of going the wrong way while putting up and lowering the mainsail, and relatively slower motoring speeds for the miles of the going out at the beginning and coming in at the end. And our course was lengthened when, due to the wind being directly behind us too slow, we took a wider turn around Frying Pan Shoals to avoid a dead run. That shoal extends quite a few miles out from the north side of the mouth of the Cape Fear River. Conversely, our course was shortened slightly when we cut the last buoy, R2, and passed near Rattlesnake Shoals off the entrance to Charleston. (That shoal is 16 feet below the surface so we could go directly over it, but why take even theoretical chances.) But the greatest variable is the wind. We had a few hours where the wind gave us less than four knots, and two hours in which we made a thrilling 8.5.

We had about three hours of very light rain in the late afternoon. One cant get rainbows without rain.


Some dolphins played with us at dusk.
Our dinner was a delicious and filling hot bowl of peppers, onions, sausages, pasta, red sauce and cheese that Lene had partially cooked before we left; we ate in the cockpit in the dark. Lene maintained the watch from 7 to midnight and I came on for the rest of the trip. It got cold during the wee hours but full foulies and gloves kept the chill out -- no pain. When Lene took over we were going only 3.5 knots on a very broad reach so I authorized the engine at 5 knots and we hauled the mainsail to midships to be a stabilizer. This was a mistake, in the sense that we wasted fuel and engine hours: sometime during Lenes watch the wind came back, and just aft of the starboard beam. So at midnight I eased the mainsheet out and we jumped to six knots. I shut down the engine and let out the genoa to play as well and our speed built to seven and eventually to variations over nine for several consecutive minutes. Eventually, we furled the genoa for the last three hours to delay our arrival. We had a beautiful sunset,

but the sunrise took place "off camera"  because heavy dark clouds blocked the eastern horizon during that event. The night time watches were quite boring due to the absence of even a single other boat out there to be seen, much less to worry about; we really had the ocean to ourselves.

The high speed portion was thrilling. ILENE seemed to be saying "I was born to go fast and Im having fun out here!" Comparatively little heeling, and not big waves, just an exuberant dash through the open seas, out of sight of land with enough light, after the moon came up, to be able to see a bit. "Thanks, Dad", she seemed to be telling me.

In my last post I worried about the auto pilot but it performed very well during this passage. We expect minor variations in our heading among strong forces out there and auto steered admirably, though noisily, with a soft squeaking/beeping sound that I need to investigate.
This bridge is just a bit upstream from us.

Im getting the spring lines in place for our arrival; end of the bridge, right.
Bottom line: we arrived in the Charleston Maritime Center at 10:30 am, 25.5 hours after we left, with an "average" speed of 6.35 knots over the assumed 162 nm.

Related Posts by Categories

0 komentar:

Posting Komentar