Kayak Garage Storage How-To

Check out 'Rope Ratchet' on Amazon or Home Depot carries them as well.  I use a bunch of these for various tasks & they work great 1-handed.

http://www.amazon.com/ProGrip-404400-Rope-Lock-Down/dp/B00138OMJI/ref=sr_1_4?s=videogames&ie=UTF8&qid=1447797271&sr=8-4&keywords=rope+ratchet

Maybe dual rig them then? 1 set of strap to get from ground to high-enough. 2nd set to get above the door, unhooking the 1st set as you go?

Here's a like to the Harken system.  This one goes to 90# but they make larger ones for the heavier boats/yaks

http://www.hoister.com/productdetail.aspx?id=6154&taxid=645