25May09

Frozen blue-bird sculptures

We ran from Petersburg to Tracy Arm Cove yesterday, and were treated to a variety of shows by the local cetaceans. First of all was a large humpback who was gradually moving across Frederick Arm, and passed fairly closely in front of Serendipity. We slowed down to get a close look at his mass (they weigh about 80,000 pounds) and he rewarded us with a sounding. That's where they hump their backs and dive, lifting their tail flukes high in the air. Gorgeous. And then he was gone.

Later on, we came across two adults and a calf feeding along the shore, and we turned to stop the boat near them. We shut off the engine and we stood outside to enjoy the sounds of silence. Well, not exactly. when humpbacks exhale, sending that huge spout into the air, it sounds a bit like an elephants trumpet, a mix of high pitched and low pitched tones. Other than the calf, who made mostly a high-pitched squealing sound. Of course, the calf wasn't exactly small. They are 4000 pounds at birth (a seriously big baby!) and likely this one was born in Baja California and swam north with its mother. But it was still a lot smaller than the adults.

After that, we came across a huge pod of Dahls porpoises. Dahls look like baby orcas, black and white with very similar patterns, at least to a layman's eye, but they are far faster. But instead of weighing thousands of pounds, they run about 250 pounds, which is about twice the size of Pacific whiteside dolphins or the familiar bottlenose varieties. (I understand that Orcas love to try to catch and eat Dahls, which is probably their version of sport fishing, given Dahls can swim circles around an Orca. But of course, Orcas work in teams.)

Several of the Dahls decided to play with Serendipity, probably juveniles, and six or so of them kept swimming along the sides of the boat and then leaping far out of the water at the bow, moving in pairs along each side of the boat. Sometimes they raced alongside and then dove just before reaching the bow, going under the keel, seemingly avoiding it by inches. We could look down over the rails and clearly seem them zooming by just under the clear water, their tails moving so fast they looked like hummingbird wings. Dahls are the fastest of all dolphins or porpoises. I think I read somewhere that they can swim more than 30 knots.

Of course, given we were only going 8 knots, they soon tired of our slow boat and ran off to catch up with the rest of the pod, which much have contained several dozen members.

We made a late arrival at Tracy Arm Cove, about an hour before sunset, and bedded down for a quiet night. We rose at 5:00am to be out of the anchorage by 5:30am, given the tide was predicted to be a -4.4 feet a bit after 6:00am and the entrance to the cove is a bit skinny.

We headed up Tracy Arm to pass the most incredibly colored icebergs, ranging from the size of a refrigerator to a city bus, with small "bergie-bits" (less than a meter in width) all around. The bigger bergs range from royal blue to turquoise in color, and given the sun was shining on the way up, they were glowing with intense color as if lit from inside. A couple of them had mighty eagles sitting on top as they surveyed their domain; others less distinguished bergs had to settle for mere seagulls.

Both sides of the steep arm were formed from glacier-carved rock that was still very young looking, as befits an active glacial fjord that is still in the midst of retreating from the last ice age. The most fantastic array of waterfalls decorated the walls, with the tops of the waterfalls so high, even looming overhead when we traveled close to shore that it was hard to crane out necks upward to see the top.

The water was steep to, often measuring 500 feet depth only a hundred feet from the walls. The shallow spots got down to 150, and the middle of the fjord was generally over a thousand feet deep. It was cold but calm and sunny first thing in the morning, with a thin overcast coming in after a few hours. The air was incredibly fresh, but not cold enough to really be called crisp (at least, not by a northerner) given air temp was in the 40's with sea temp in the upper 30's.

We amused ourselves by imagining what creates the wildly shaped bergs resembled, for many of them were true works of art. We found the ultimate when we found a small berg grounded at low tide on a sandy beach that looked exactly like two birds sitting side by side. I've included pict in this post.

Unfortunately, the ice grew thick quickly, probably due to the 23 foot tidal range of this very deep spring tide. I've read that a large tidal swing causes increased calving of tidewater glaciers. Friends who were in Tracy Arm only a week ago on the neaps came very close to the glacier, but we found a solid wall of ice about halfway up that looked thick enough and big enough to walk from shore to shore.

A huge cruise ship came in after us and tried to push through the ice field, and I entertained the idea of following closely behind in his ice-free path, but Debbie was not so keen on that. In any case, the cruise ship only went another half mile or so and also turned around. If the ice can stop a thousand foot steel-hulled cruise ship that was designed for northern latitudes, then I'm glad I didn't try to push it with my plastic boat.

We debated staying another night in Tracy Arm Cove as it's a very nice spot, but decided in the end to run north to Taku Harbor. Winds and seas are supposed to be up on Stephens Passage tomorrow and we might as well make some more northward progress while the water is glassy smooth today.

Speaking of smooth, we had to struggle a bit to get out over the bar at Tracy Arm. The current guide said we should expect a 1.5 knot flood current at the bar, which is no big deal, but they were way off. We approached the bar as the water rose off that -4.4 foot low, and all looked fine except we couldn't see the green marker. No big deal, Douglas says bergs can carry the buoys away, but it was there last night. Fortunately, there is a range just outside the bar that showed us the center of the bar opening. But as we came closer, I found I had to crank in more and more rudder, and eventually was pointing 70 to 80 degrees off my course and I was still drifting left, and appeared to be stopped. I added more and more power, finally firewalling the engine just to keep moving and in the channel. We finally saw the green marker, or at least the ripple on the surface where it was swimming underwater! The red buoy was almost underwater as well.

I estimate the current was 7-8 knots, because with full power, which should give me close to 10 knots, I was barely staying over 2 knots .Not to mention having to aim almost directly at the location of the (underwater) green marker just to stay in the middle of the channel as I crossed the bar. Yet the water was completely smooth, giving no indication of the racing current. In fact, if I hadn't been watching the range, I might have wound up on the rocks before I realized how strong it was running. When I looked down at the nav system course predictor, it had me going nearly sideways down the bar. We hung in the middle of the pass (between the rocks) for so long that I began to doubt the veracity of the SOG (Speed over Ground) display that showed me moving forward at 2 knots.

Yet all the while, it was as smooth as a lake. Weird.

Lesson 1 learned: If you don't see the buoys, then assume they are underwater due to an extreme current.

Lesson 2 learned: Flat, laminar flow water with no evidence of up-wellings, swirlies or overfalls doesn't always mean there isn't a killer current working you.

1500: Anchored Taku Harbor. The harbor appears deserted, but has two new floats of significant length, both public, but we prefer our ground tackle to most floats, so we anchored as usual. It's supposed to blow a bit tonight.