"WHERE IS the water?," you might find yourself wondering at some point as you wander through the American Visionary Art Museum's newest, aqua-themed exhibition, "Holy H2O: Fluid Universe."

I'm not talking about Baltimore's Inner Harbor either, the view of which will soon disappear as construction proceeds on the Ritz-Carlton Residences, a luxury condo project taking shape just across the street from the museum and its new wing (scheduled to open to the public Nov. 16). I'm talking about art.

While water is certainly prominent in this show -- most notably and literally in a burbling fountain at the center of a mermaid-centric installation by artist and voodoo practitioner Nancy Josephson -- there are certain works whose connection to the sea around us is tangential, or technical, at best. Washington artist Matt Sesow's "Out of Water," for example, which depicts, in deceptively prosaic fashion, a man in a wet suit, or Los Angeles-born Christopher Moses' twisted, Disneyesque, cartoon sea creatures may strike you initially as having only the most tenuous connection to the notion of a "Fluid Universe."

That's probably because asking "Where is the water?" is asking the wrong question to begin with. "Where isn't it?," the show seems to reply.

Water, after all, doesn't just reside in the oceans, streams, lakes and swimming pools of the world, but in the very air we breathe. It's in the snow and ice of winter, the rains of spring, the humidity of summer and in the leaves that fall in autumn. It's in the fruits and vegetables we eat. We drink it, sweat it, bathe in it, excrete it and then, further down the line, drink it in again. We are, in fact, mostly made of it. It is there even when it doesn't appear to be there.

That's one reading of "Fluid Universe." Water is primal, ubiquitous. It's why so many of us are drawn to it like lemmings, as is so evident in Tom Duncan's "Dedicated to Coney Island," a wonderfully sprawling, miniaturized and motorized rendition of the beachside resort that, along with Josephson's room-size sculpture, hogs the show's center stage.

The other reading plays on the double meaning of "fluid," not just as in liquid but as in flexible, in flux. For "Holy H2O" is as much about a state of being as a physical substance. To that end, there's a strong component of the spiritual here. ("Holy," anyone?) Water, in all its plasticity, is a metaphor for the soul. That word may be anathema to some, but never at the Visionary Art Museum, where the creative spirit is sacred.

There are always so many themes and sub-themes percolating up through everything this museum does, and this exhibition is no exception. Pollution, the history of the ship-borne slave trade, ritual ablution, even hints of the River Styx make appearances here. One could argue that, by throwing so many ideas in the soup, the museum has unintentionally diluted its own thesis.

I would argue that the opposite is true, that the show is, paradoxically, more, not less coherent for all its liquidity. Yes, the show is slippery at times and takes many forms. Just as soon as you think you've gotten your hands on it, it runs through your fingers. And yet it provides refreshment and rejuvenation, even as it frustrates our desire to hold it still.

Just like water.

HOLY H20: FLUID UNIVERSE -- Through Sept. 4 at the American Visionary Art Museum, 800 Key Hwy., Baltimore. 410-244-1900. www.avam.org. Open Tuesday-Sunday 10 to 6. $9; children, seniors and students $6; groups of 10 or more $5 per person; ages 4 and under free.

With next month's opening of the Jim Rouse Visionary Center, a converted whiskey barrel warehouse housing classroom, exhibition and public program space, the museum's prices will increase by $2 in all categories, beginning Nov. 16. Children ages 4 and under will still be admitted free.

Water plays a visible role in many of the works in "Holy H2O: Fluid Universe," including "Mermaid," by Christopher Moses.In other works, signs of water are less obvious, as in Carlos Zapata's "The Carnival" at the American Visionary Art Museum.