Q: how do I have to do to have the dock visible in full screen?

Full screen in Safari appears to turn on the option to hide the dock when not in use on weather or not it is selected to the user. Is that the issue you are having? If so it appears to be behavior by design.

To hide the dock double click on green dot .

And to view it once again click one time again on green dot .

Full screen is meant to concentrate on the application you are working on. The Dock being visible detracts from that, so it is set to disappear, by design. I don't think you can change this behavior, but why would you even want that? I dare say, even when not in full screen, there is little point in keeping the Dock visible at all times. Just sayin'...

OS X El Capitan: Window basics

FWIW, if you go to System Preferences > Dock and change "Double-click a window's title bar to" zoom, it will Maximize an app's window. That's as close as you can get.

Please add one more option in my post , go to system preferences dock - check the box automatically hide and show the check box .

As a couple people pointed out, it is not possible to see the dock when in Full Screen Mode. However, you can Command + Tab back to the desktop, use the dock there then Command + Tab back to the App that is in Full Screen. Or, as I mentioned instead of Full Screen you can maximize an app to take up most all of the screen except the Menu bar and Dock.

If you can see the Dock, it wouldn't be full screen. That's pretty much the defintion of full screen.

If you want to see the Dock, don't use full screen mode, just maximize your window.

mariefromnewengland wrote:

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At the Apple store the other day I looked at a new 27" iMac that showed the dock on a full screen app; I want it right now, but I'm afraid I won't get it.  Thanks for answering.

You're welcome.

I don't know what you saw at the Apple Store but it wasn't the Dock showing while an app was in full screen. Of course you can always go back to the store and ask them how they did it. Certainly it's not possible in El Capitan.

mariefromnewengland wrote:

 

That's what I've been doing, but I don't like it.

As it turns out, everyone was wrong including me. lol

When you have an app in full screen, swipe at the bottom of the screen, twice.

Apparently this has worked since OSX 10.7.