Firstly, I should point out that author Kristine Kathryn Rusch is using ' diving' as the aquatic metaphor for examining derelict spacecraft. Considering we call space vehicles ' spaceships', seeing the vacuum of space as a sea shouldn't be that much of a surprise although it only really disguises the term extra-vehicular activity. Although Rusch's future period has no date, I do wonder if a 20th century metaphor would still be used in the future.
http://www.sfcrowsnest.com/articles/books/2012/Diving-Into-The-Wreck-book-1-by-Kristine-Kathryn-Rusch-16787.php
