Jon Dawkins (http://3meterswell.blogspot.com/) contributed the following by email:
They are at Islet 48. A very cool camp site and and a strategic one, too. Since they set off the Spot at 11:13AM I'm pretty sure that they went through Gale Passage. Gale splits Athlone and Dufferin Islands and is very narrow on both ends with a large "bath tub-like" lagoon in the middle. During flood tide water enters both the north and south ends to fill the bath tub. On ebb the flow reverses and the bath tub empties into Seaforth Channel and Queens Sound. Timing is important here as there is a fair amount going on. If you look at the chart at this link you can see the passage, the bath tub and the rapids at both ends. The body of water at the top of the image is Seaforth Channel. The water at the bottom of the image is Thompson Bay which opens into Queens Sound.: https://picasaweb.google.com/lh/photo/8zhF6r02QZ8ASI278e5y6w?feat=directlink
There is an image from Gary Luhm's website showing the north rapid of Gale Passage. I encourage you to visit his website and check out his images. It is under Galleries/Seakayaking/British Columbia. and described as an "Unnamed Bella Bella Tiderace": http://www.garyluhm.net/home.html. The south entrance is wider and a lot more water flows in and out. We've been stuck there before.
This image looks south from Islet 48 to the McMullin Group, a stepping stone to the Goose Group: https://picasaweb.google.com/lh/photo/NWFkqSuOVZIv6aJULIQcVQ?feat=directlink
If they go south to McMullin and Goose they commit to a long-ish crossing of Queens Sound to get back to the shelter of the passages.
Today's straight line distance was about 11 nautical miles. If they took the route Jon suggests they traveled a remarkably straight course.
The kmz archive:
The daily file: