Speaking of overflows, you might want install it over a shower sump or rig a pan under it, just in case. Washer "overflows" and other problems are common enough that some city building codes require some type of basin/drain under them in building laundry rooms. A boat's got a bilge...I guess the only question is how much of a mess the water can make en route to it.
I'm told those little hand-tumble washing machines (more like a wide-mouth minibarrel) do a pretty good job, they're just limited capacity and all hand work. But, cheap and light and small.