SHIPS AHOY!

HOW TO MAKE A REPEATING STRIP PATTERN

1. Select the Rectangular Marquee tool and draw the line you desire.
2. Select the paint bucket tool (underneath the gradient tool) and fill the lines with the color you desire (you can do this through the picker or the color libraries)
3. Repeat steps 1 and 2 until you have the variation of lines that you want (for this one I drew 1 thick blue line, 1 thin white line and 1 thin red line) 
4. Now go up into Edit --> Define pattern and define the pattern area
5. Open up a new document to desired size 
6. Select the paint bucket tool. On the options tool bar you can choose between either foreground or pattern. It will probably be set to foreground so open up the drop down menu and select pattern, then select the pattern that you just created and fill the page. It will repeat automatically. 

Select from the drop down menu your pattern