Inbound Charleston from sea

We are in the Atlantic Ocean east of Isle of Palms, South Carolina (map).  Even though today's ocean forecast was identical to yesterdays, seas are, in fact, much calmer today, with an almost glassy appearance along a good part of the route.  That made it easy to spot several dolphins, although we did not see any whales today (so far).

The price we had to pay for such lovely conditions out here was to leave in pea-soup fog this morning.  A dense fog advisory ran until 9am, and even though we were up at 6, we waited until 8 to have the best possible visibility.  A 9am departure would have put us into Charleston after sunset, and that harbor can be very confusing after dark.

We adjusted the radar as best we could, and picked our way back out into the ocean by following our breadcrumbs and the radar returns from the buoys.  We also fired up the massive Kahlenberg automatic fog horns, which had both cats scrambling for cover.  These sound at roughly one-minute intervals, and I confess that it even takes the humans a few minutes to stop jumping every time they go off.  The fog burned off about an hour after we made the turn at the end of the south jetty.

Last night we collapsed early, after a hearty dinner and a couple of glasses of wine.  We were beat from a long day, and also we had no Internet access to speak of -- my phone kept going in and out of coverage, and it was all I could do to post the blog I had written earlier in the day.  I could not post the photo I had of the teak shower stool, nor could I correct my, umm, faux pas, wherein I had written that it was faux teak -- Louise, upon reading it later, corrected me indignantly, as it is a hunk of actual teak instead.  The gaffe is now corrected and the photo has been added to the post.  Somehow Blogger overwrote my post date, however, so I had to take a guess to fix it.

We had very securely anchored with 180' of chain in about 26' of water, and we watched the boat swing both directions in the current so we thought we'd sleep soundly.  Nevertheless, we were rudely awakened around 1am by a screech, followed by whirring.  I ran on deck to hear water churning past the stern, as if we were under way, and Louise yelled up that the prop shaft was turning.  The current had picked up to over 3 knots, and the whirring sound was the gearbox as the prop windmilled at something over 100 rpm.  We guessed the screech was the shaft overcoming the "stiction" of the cutless bearing as the relentless current finally set it spinning.

A freewheeling prop on a marine transmission can be a real problem, and I am embarrassed to say that we had not researched beforehand what to do about such an event with our particular transmission.  When we had been looking at twin-engine boats, I had paid careful attention to transmission models and what we'd have to do in the event we needed to run safely on one engine only, but the ZF280 was not one of the models I had researched.

The good news is that even in the heavy current, the anchor had not moved an inch.  I quickly started the main engine to get lube oil flowing to the transmission and raw water flowing into the stuffing box, and we ran the engine at 900rpm for the next hour while we tried to figure out what to do.  The manual we found on board, for a slightly different model, was no help, as it made no mention of freewheeling.  And doing further research was difficult with almost non-existent Internet coverage.

After an hour of hammering at it we learned that most hydraulic-clutch ZF models can be freewheeled with no harm so long as the temperatures remain low.  I could tell the gears were splashing in oil, so that made sense. We also checked that plenty of water was coming in through the stuffing box while the prop spun freely in the current, making me extra-glad we opted to switch out the dripless style for a conventional packing gland and stuffing.  A quick check with the IR pyrometer revealed nothing but cool temperatures, and we went back to bed with the 100+ rpm whir in the background.

Of course, we'd anchored and docked in currents above three knots many times in the past, and it took us a while to realize why we had not experienced this before:  this is the first time we've done so since we replaced the shaft and bearings and had the whole driveline aligned.  Unsurprisingly, it takes less force now to windmill our propeller.

The run from Winyah Bay to Charleston is much closer to land than yesterday's run, to the point even of having a dog-leg in it to go around Cape Romain Shoal.  Now that we're less than ten miles offshore of a number of populated communities, we've had pretty good Internet access on and off for the last hour or two.  I thought I would take advantage of the calm and empty seas to get today's post written; tonight we should be anchored off Fort Johnson just inside the Charleston Harbor entrance.

Our reservation at Charleston Marine Center does not start until Sunday, although I will call them to see if they've had a cancellation earlier.  We'll stay anchored in Charleston Harbor until they are ready for us.  I am looking forward to a week of downtime to get some projects done and take in some more of Charleston proper.  We've also had our mail forwarded there along with a number of items we've ordered in the past week.