After 21 days at the Costa Rica Dome, we could stay no longer and turned north for Acapulco.

On the voyage home, we took stock. There had been disappointments: We wished we had satellite tagged more whales, had seen more calves, had experienced more underwater encounters with blue whales. We were sorry not to have glimpsed whale 4172, the white bull. But for the most part we were satisfied.

In three weeks spent crisscrossing the dome, we had succeeded in finding three whales satellite tagged in California and tracked down here. Each time we homed in on the transmissions of one of these telemetric whales, we had found it in the company of "clean" whales. Satellite tagging had proved itself an efficient method for locating concentrations of the untagged. We had satellite tagged three new blue whales (but one tag failed to transmit), affixed acoustic tags to six more, and photo identified about 70. Thirteen of those 70 were from California. The voyage proved that the dome is visited by large numbers of blue whales. We saw many threesomes, the romantic triangles of the blue whale, and we witnessed much boisterous courtship behavior, all suggesting that the dome is a mating ground. We demonstrated beyond a doubt that blue whales do feed here in the winter. With sonobuoys and acoustic tags, we eavesdropped on A and B calls of the blue whale song and on the D calls whales make between bouts of feeding, and thus began notation of the winter music in this patch of ocean.

The news from the dome is good.

The grandest creature in all creation has been hunted by our kind, the thinking ape, to near extinction. Its numbers still are low, but it was hard not to feel optimistic. In my bunk with Nicklin's laptop, lingering over his dig­ital portraits of the curious calf, I thought I could read, in its strange visage, a gargantuan impishness. I found this cheering. The young do give us hope.

On the voyage home, we found time for reflection, and I understood why the blue whale's flukeprint so mesmerized me each time I saw it at the dome. That big, circular slick is the sig­nature of the species, the John Hancock of flukeprints, outsize and insistent. It jumps out boldly from the parchment. Its uncanny persistence on the sea's surface, defying the choppiness, is a good omen. Appearing at the dome, this winter haven, it suggests that the blue whale might after all defy the chop of history.

"Still here!" the flukeprint says.