Per the rulebook:

WATER: shallow water features, such as streams and ponds, are treated as hindering terrain for movement, but have no effect on ranged combat actions. Characters with the Aquatic symbol on their base treat water terrain as clear terrain.


Now, can those with the Batman Ally Team Ability HIDE in the stream and pond and be Stealthed? What of larger bodies of water (if they ever put one on a map)?

I'd probably say "no" as it has "no effect on ranged combat..." Only thing it does is slow grounded figs down.

I'd say "yes" because it has no effect on ranged combat if the line of fire passes OVER water (i.e. if Batman is on the other side of the pond, but not in it), but if the fig is IN the water, then he is protected.

Judge?

The line being quoted in Thorgrin's post is from the rulebook's hindering terrain section, specifically the part devoted to water.

Water is hindering for movement, but not for LOF. Stealth figures cannot use it to their advantage.