I couldn't get a book with this tale earlier than some days ago, so I read it and listened to the discussion on the podcast only this day. (I read it in 'Men of the Deep Waters' edited by Denton & White 2013.)
For me, this surely was one of the best reads for and best discussions in Elder Sign. When reading I already noticed the great writing skill of WHH, and this was explained and deepened in the podcast. I liked the discussion because of the creative writing approach that was dealing with some of the problems I come across when writing.
When I read a story that appeals to me, I always try to find out WHY it think it's good, but more often than not I can't figure out what it is exactly. Correct me if I'm wrong, but I extracted these four creative writing tips out of the podcast:
A good evocative setup raises intriguing questions for the reader: in this tale these are the eerie 'sea swamp', the vast expanse of the sea that makes men lonely and insignificant ( - really cosmicist thing - ) and the strange shipwreck, among other things.
Don't loose sight of the humanity of the characters in the story: the Christmas scene showed that there are other things that the people in the story are concerned with outside the core plot; this makes the tale more real and so, in a way, more terrible.
Only use a frame story when it is needed: the frame in From the Timeless Sea is used by WHH to give information to the reader that couldn't be given in another way (i.e. Philip and his wife and daughter must be dead by now - how horrible), and to reinforce the theme of nautical legends by introducing the nautical world.
Mythos/universe building can be used to plant seeds for other stories. These seeds should be introduced in an organic way though, otherwise they appear out of the blue and should be deleted when editing your story. A landscape (this tale), artefact (The Hobbit/LotR) or something else (e.g. references to the Elder Ones by Lovecraft) can be used as a seed to deepen the mythos, create expectations by readers to read more tales (returning to a familiar world) and give the writer a framework in which to experiment with different angles to the stories and themes within the same world.