Water walking is a property that allows you to walk over fluid environments without drowning. This affects moats, pools and swamps as well as lava. As fountains and sinks do not cover a complete square, there is no extra effect while water walking for them. The most common source of being able to walk on water is by wearing a pair of water walking boots.
While water walking, you may safely enter water-based squares listed above and not fall in and potentially drown. Additionally, if your water walking boots are fireproof, you can walk across lava - but you will sustain damage unless you have fire resistance. Attempting to do so without fireproof boots will burn them up, and you suffer the effects of the lava as normal.
Players walking over water can #dip as much as they want without fear of releasing monsters as with fountains. Sea monsters (;) become more of a threat to them, however, as the property doesn't provide protection from their drowning attacks.
If standing on a water tile, do not displace a pet unless they can swim or fly, or else they will drown when swapping places.