Chongo wades out into the cold water, and gives the floating corpse a poke with his spear. To his relief, it does not respond in any way to being disturbed. A closer look reveals that the body is water-bloated and crab-eaten, making any sort of identification process very difficult, but it doesn't seem too old. A quick examination reveals that the corpse has nothing of value upon it.
Anar proceeds to examine the various sodden doors leading from the room, but he turns up nothing dangerous or interesting. He also doesn't hear anything noteworthy from beyond any of them, besides the previously mentioned sloshing sound to the west. (Listen, Search Checks)
Kalen summons his twinkling lights again (casts Dancing Lights), then proceeds to dive into the sloshing pool, intent on discerning whether any escape route lies below. This water is marginally less disgusting than that of the previous pool, but it's still unpleasant. Plunging under the surface, Kalen's sharp eyes quickly detect that there is indeed a series of submerged tunnels in the southern wall of debris. Unfortunately, the waterways appear too small to enter. In a few spots, the tunnels are a bit wider than a foot, but for the most part they are much narrower. With some contortion and luck, a halfling or gnome might navigate them, but all of the present party members are certainly too big to fit. These tunnels are best suited for crabs, it seems.
As Kalen begins to rise toward the surface with his disappointing news, the glimmer of something shiny catches his eye from the bottom of the pool. (Search Check)
Col, meanwhile, gives Keoni another dose of healing with a tap from the bone wand. (-1 charge; Keoni gains 4 hp, to 13/17 hp).
edit: Anar's listen check does reveal the sound of sloshing liquid to the west.