I had mentioned that I had a problem with Jasper splashing and dumping his water all over the floor. It's been about six weeks since I found the solution, and it does seem to be working. (Photo from Amazon.com, "Greedy Pup-Best Slow Eating Bowl on The Market", by Greedy Pup.
It's meant to slow down dogs who eat too fast. For Jasper, I fill it with water to the tops of the bumps. It's a hair over 9 inches wide and heavy, so he can't tip it, drag it, or pick it up. The bumps prevent his making tidal waves, but still allow him to make satisfying splish-splash noises, and there's enough room between the bumps that he can drink easily. The sides are not quite high enough to bother his cyst.
It wasn't his splashing that bothered me, it was his emptying the water all over the floor, so this seems to be a good compromise.