Anyone got any info on a boat moving device?

[BearLakeFishGuy]

My old neighbor has one like that (power boat mover).  It easily moves his 18' aluminum boat/motors on his grass yard.  I've been thinking about one of these but for now I can muscle mine around on my paved driveway.  I only have 1.5" of clearance on each side of my wheels when pushing it back into my garage, so there is VERY little room for error.
Amazon.com: Trailer Dolly Depot TDD3500 Electric Trailer Dolly for 3,500 lbs Gross Weight or 350 lbs Tongue Weight with 1 ⅞” and 2” Hitch Balls : Automotive