My wife prefers towels that dry naturally in the sun and wind. Our outside deck is close to our laundry area so I looked at what I might be able to do while keeping the original deck appearance as much as possible and disguising the clothesline when not in use.
Step 1: Determining Height Above Deck Floor
We determined that 79" was the optimum distance from the deck floor to the hook.
Step 2: Mounting the Swivel Hinges
I used two gate hinges (4" size) from Lowe's. Cost around $2 dollars each.
I mounted the hinges as shown to the existing 4x4 support posts and the hideaway 2x4 for each side of the clothesline.
Step 3: Adding Clothesline Hook
Pilot drill appropriate hole in the 2x4 and screw in the hook on each side of the clothesline.
Step 4: Appearance When Not in Use
Here's what it looks like when not in use. The 2x4 swivels on the gate hinge against the the 4x4 support post and blends in with the deck. Last step is to stain to match deck color