Your VAB and ship files should be in ~/Library/Application Support/KSP_osx/saves/[YourSave]/ships/ on OS X.
The location of the real Library folder is a bit different on Mountain Lion (OS X 10.8), you will need to use Finder to get to it.
Select "Go" (Or press Command + Shift + G ) from the system menu
Then select on "Go to Folder" (skip this step
is you used the keyboard shortcut) Type in "~/Library/Application Support" and then "Go."
On Windows, the same files should be in the folder at %KSP_ROOT_Directory%\saves\...
gaming.stackexchange.com/users/15772/Krazer
Yes, this is actually fairly easy.
All of your save data is stored in plain text files as a subdirectory of the saves folder in the main KSP folder.
Each save game has its own folder, which includes subdirectories for VAB and hanger ships.
Simply copy the desired folders (be it the entire save or just a few .craft files) to the new install location.
gaming.stackexchange.com/users/1351/MBraedley
I'd like to note if you have KSP on Steam on OS X, here's where the ship saves live: ~/Library
/Application Support/Steam/SteamApps/common/Kerbal Space Program/saves/<save name>/Ships/ Note the spaces in the path.
gaming.stackexchange.com/users/12407/Steven Lu
You can even put the files in something like dropbox and then make aliases/shortcuts from the save game directory and have them shared between computers.
Just don't play it in more than one place at a time.
gaming.stackexchange.com/users/12946/xaxxon
On Mac using the GOG-Version of the game and using the GOG GalaxyClient the save files are actually in the *.app Application-File itself.
Locate KSP in the Finder and do a Right-Click >
Show Package Contents and navigate to Contents/Resources/game/saves .
gaming.stackexchange.com/users/142770/stephan
I've been playing KSP on a Mac, but I'd like to transfer all my save data over to a Windows PC. Is this possible? If so, where are the files and what do I need to transfer?
Can I transfer my saved game between platforms?
gaming.stackexchange.com
<kerbal-space-program>
gaming.stackexchange.com/questions/97457
gaming.stackexchange.com/users/3610/fredley
All your saved data is stored in plain text files. You can even put the files in dropbox. It is possible to transfer Kerbal Space Program saves to other systems and operating systems.
The community is pointing the location of saves. A user is proposing a way to share saves in multiple platforms.