Anybody Use A Motorized Boat Dolly/Mover?

Hey Guys,
Parking my boat is a bit tougher than I thought. I can get the boat in my warehouse, but need it in the very back and then 100% sideways to keep enough room for my work trucks too. Getting the boat sideways is the problem, it's a Ranger Z520C on tandem trailer. I need to get the boat completely sideways and can only get it halfway which wastes a ton of space. Been looking at some of these electric/motorized dollies which look like exactly what I need. Anyone else use one and if so what model, does it work and how much?
Thanks!

I use my boat way to often to go thru that kinda trouble.

Burner 42: You may want to check into a trailer valet for moving your boat. I have one I use to take my boat out and back in and it has saved me a lot of problems. They have one you can move your boat with a drill. Just some thing to check in to.

I think I figured out a better way, I own a landscape maintenance business, I think a riding mower with a hitch welded to the front will work much better, plus I can pick one up for $400ish used. My warehouse is 80' deep 28' wide, it would be easier with a tractor, plus I will have brakes if needed.
Keep the suggestions coming, still open to ideas.

Are you familia with gojaks? Put one under each wheel and you can push/turn that boat all over that warehouse by hand. You could spin it in circles if you wanted.

Their are now cheaper knockoffs available but a YouTube search for gojaks will show you what I mean.

EDIT: this one is only 37 seconds but you'll get the idea

https://m.youtube.com/watch?v=mRfJy-o0ujQ

@KD- Those are exactly what I need! I have a level concrete floor. I just ordered a set of 4 Dragway 1500 lb wheel dolly's for $359 with free shipping. They got several good reviews online too!
I'll report back how they do after I get them.

https://www.amazon.com/gp/aw/d/B003W0F33O/ref=mp_s_a_1_6?ie=UTF8&qid=1478239009&sr=1-6&refinements=p_4%3ADragway+Tools&pi=AC_SX236_SY340_QL65&dpPl=1&dpID=417SZm5RMvL&ref=plSrch

Thanks Buddy!

To get my boat into the garage I first have to back it down a 200 foot driveway then jackknife 90 degrees in front of the garage door. I have just two inches from the trailer fenders to the garage door frame on either side. Then there's a one-inch step from the driveway to the garage floor that makes it pretty difficult to push the trailer in by hand.

I built my own trailer mover from plans I bought online. I still needed to do some significant re-engineering to size it to my needs. It uses a modified ATV winch. I pull power off of a third wire I added to the troll motor receptical.

That is one awesome looking machine there. I have the trailer valet and it works for me, But if I had one of those , it would be like no work at all. Congrats on your trailer valet there. Awesome ,awesome.

I use a riding mower. Your mover looks good.

I used to have to put my boat on dollies and move it behind my house due to my HOA, what an absolute beating. they would get stuck in expansion joints and shoot out from under the wheel.
if you have a really smooth floor wheeldollys should be fine harbor freight has them pretty cheap

Hey Phish, thats an awesome unit you built! I would be interested in something like that, but I already purchased the wheel dollies, and my buddy is selling me his John Deere 42" riding mower for $300, Im going to weld a hitch to the front of it ! He sold his home and does not need it! I figure between the dollies or the tractor I can wedge that thing anywhere I want!
Thanks for the replies and photos!