Had to go back a bit in the book to find coastline (tricky Trillian), but the only coastline I could find is good old Slartibartfast and his fascination with fjords -- "doing the coastlines was always my favourite," he says. [chapter 22]
Did you know that Canada has the world's longest coastline? -- 265,523 km, or 164,988.3 miles [conversion by Google]. The figure varies a little according to which source you use, but it is still more than twice (not far from three times) that of Indonesia which comes second. It's all those little islands in the Arctic, I suppose, and being the second largest country in the world. When we talk about the vastness of this land we say from coast to coast to coast (because we have three oceans).
Now what to quill for coastline Best I could come up with is a lighthouse to guard all those many miles and the ships that pass by. I even included a little gem for the light.
Come visit Canada some day - it is truly a glorious land. And according to Lonely Planet it's the best travel destination in the world for 2017. And 2017 is our 150th birthday.