The huge wave image used as the default wallpaper for OS X Mavericks is certainly striking, but if you don't harbor any particular affinity toward surfing, or the ocean in general, you have other options. OS X has some options readily available on the Desktop wallpaper screen in System Preferences, but you'll notice there are different images available on its Screen Saver page, where it lists four Default Collections: National Geographic, aerial, cosmos, and nature patterns.
Count the images and you'll see there are 43 images across those four screensaver collections. You can use these images as your desktop image by locating them and dragging them one at a time into the Desktop page in System Preferences.
To track them down, hit Command-Shift-G from your desktop to open the Finder's Go to Folder window. Next, enter this path:
/Library/Screen Savers/Default Collections/
Browse through the folders and then drag an image into the Desktop window of System Preferences.
reading•Where to find 43 hidden wallpaper images in OS X Mavericks
Apr 21•2018 iPhone may cost half the price of an iPhone X
Apr 21•Google wants to kill SMS texting, Tim Cook says iPads and Macs aren't merging
Apr 20•Apple HomePod: Here are the apps you can use with your voice
Apr 20•iPhone SE 2 won't have a headphone jack, report says