Here's an item you won't see for sale at your local hardware store. I'm going to call it a "gondola dolly".
I'm sure it can be used for many things, but I shot this photo in Squero San Trovaso, where it was being used to move boats around.
I remember Joe Gibbons of Boston described these things to me once after visiting a squero on La Giudecca. Joe said he watched the squerarioli as they lifted a gondola onto one of these.
After that it could be rolled around by one guy without much effort. Two little wheels on a crosspiece, and one guy can move a 36' boat anywhere he wants.
A closer look at the ground reveals a Monet-like smattering of paint chips from countless gondolas, which have been built and serviced here since the 17th Century.
I wonder when the "gondola dolly" was invented.