His seas are seldom calm -- they boil and they roar. Sunsets rip his skies. The North Atlantic seascapes of the aging Winslow Homer must be among the grandest ever made by an American. "Winslow Homer in the 1890s: Prout's Neck Observed," the touring show now visiting the National Museum of American Art, brings us 15 of his oils. It's not a large exhibit. It nonetheless feels mighty. When you step into the gallery, the beauty of the paintings -- their drama and ferocity -- almost knocks you down.

Their colors sock you first. They're amazingly intense. The whiteness of his whitecaps makes you squint into the brightness, and even when he uses the softest grays and tans -- for a wind-swept dune at dusk or a blanketing of fog -- his pictures seem alight. Equally impressive is the freedom of his brushwork. His marks aren't smoothed or polished, and yet they conjure perfectly the glassy green of heaving seas, the sheen of wave-washed rocks.

For 27 years, from 1883 until his death in 1910, Homer chose to live at Prout's Neck on the shore of Maine. His studio is still perched there on the cliff. It's become a sort of shrine. Homer knew by heart the shore he chose to paint. Decades of observation inform his every brushstroke. His explosions of white spray, his wind-bent shrubs of juniper and his shreds of kelp and sea wrack are utterly convincing. And yet his pictures have a spirit that's surprisingly theatrical, as if -- in their collisions of the liquid and the solid -- life was meeting death.

Homer was for years misread. He once was thought a realist who mechanically depicted only what he saw. "Homer's style," wrote the painter Stuart Davis 60 years ago, "is no style at all, but the natural method of a man who has seen a lot of photographic illustration and likes it." But what was Davis looking at? The surfaces of photographs are flattened-out and dead. Homer's are alive.

And yet, as Davis saw correctly, all of Homer's paintings feel like illustrations. They're storytelling pictures. Not just elemental forces, but human feelings too are battling within them. Fear competes with courage and despair wars with hope as those great Atlantic rollers, like heavy sliding mountains, explode against the stone. Scary sea yarns haunt these pictures. As their gales howl around you, you can almost hear, afar, the screams of drowning sailors and the staving-in of hulls.

Homer's Prout's Neck seascapes are the opposite of prissy. They're hymns to the heroic. Homer's North Atlantic is not James Joyce's great green mother, his moonlit waves are never backgrounds to romance. He made macho art.

His earliest known drawing, sketched on the endpaper of his copy of "Boy's Treasury of Sports, Pastimes and Recreations," shows a lone man fishing. Strong men without women, and the harsh-yet-beautiful environments they battled, were, throughout his life, the chief subject of his art.

His soldiers made him famous. Homer, who was born in Cambridge, Mass., in 1836, earned his reputation with his reportorial sketches of the Civil War. Later he would paint shipwrecked sailors, fishermen, hardy bearded trappers. In place of fallen warriors, his wondrous watercolors show us dying deer or ducks or trout. He never lost his love for campfires and gun-smoke, for male bonding, roughing it and blood.

There is, despite his seriousness, his somberness, his genius, something not quite grown-up, something almost boyish, in his grand outdoorsy art.

The first painting in the show, "Cloud Shadows" (1890), shows an old and grizzled salt seated on a sandy beach, conversing with a maid. The old man, in his foul-weather gear, seems a figment of the landscape. The girl, in her embroidered shawl, is a creature of the parlor. He's convincing, she is not. The glances they exchange suggest Othello's explanation of his bond to Desdemona: "She loved me for the dangers I had passed, and I loved her that she did pity them." Most of Homer's women are less than quite believable. Some -- dismissed by Henry James as "pie-nurtured maidens" -- are too innocent and sweet. Others are too Michelangelesque -- they look like men with breasts. Most of these are fisherfolk. Thick-armed and thick-legged, and bearing nets or creels, they tend to stand ashore alone staring into space toward their strong men out at sea.

Homer's hymns to masculinity, and with it his implied suspicion of the feminine, reflect a deep strain in our culture. Huck Finn on his drifting raft and silent Natty Bumppo, Hemingway's Nick Adams fishing in the woods and Joshua Slocum aboard Spray, sailing round the world alone, are among the painter's soul mates.

Looking at his pictures, we too are asked to see ourselves as strong and fearless males accustomed to the dangers and powers of the North Atlantic. Homer's Prout's Neck seascapes -- and the legends they encouraged -- invoke an image of the artist as a kind of fearless loner. Far from friends and family, and immune to discomfort, he is wandering the shore, or busy at his lonely work in his spartan studio above the booming sea.

"Homer, like Thoreau, is a recluse, for the reason that the art of the sort he lives for is incompatible with the amenities of society," wrote William Howe Downes and Frank Torrey Robinson in 1896. "He lives in a lonesome spot on the coast of Maine. His sole companions are natural and uncomplicated beings, outdoor folk, hunters, fishermen, sailors... . "

But that's not exactly true. As Patricia Junker, curator of American art at the Memorial Art Gallery of the University of Rochester, who organized the show, and the scholars who have written for its admirable catalogue -- Philip C. Beam, David Tatham, John Wilmerding and Lois Homer Graham, the grandniece of the painter -- take pains to remind us, Homer was no recluse, nor was his move to Maine all that idiosyncratic, nor was Prout's Neck all that rugged, nor did he live there all alone.

Prout's Neck was to the Homer family what Hyannis Port is to the Kennedys -- a bustling family compound conveniently located in the midst of a resort. The painter's parents summered there, and so too did his brothers, their children and their wives. So too did many other prosperous and worthy folk from Princeton, Philadelphia, Boston and New York. Had the artist really yearned for isolation, he would not have worked so hard finding summer renters for the various cottages -- "Black Rock" and "the Briary," "the Walnuts" and "the Coop" -- that he built and managed on the family's Prout's Neck estate. Solitude be damned -- there were profits to be made by selling sites for cottages in the booming resort market. Between 1903 and 1910 the painter sold off 40 lots of Homer family land.

"Prout's Neck in season was, for the artist, the social equivalent of the Century Club in New York or the North Woods Club in the Adirondacks -- a special place where he shared the stimulating company of many of the most prosperous and learned people to be found in late nineteenth-century America," as Junker notes.

Nor was Winslow Homer the first painter of the day to find New England resort living entirely to his liking. As Wilmerding reminds us, many other painters -- among them Thomas Cole, Fitz Hugh Lane, Frederic Edwin Church, William Stanley Haseltine and of course Childe Hassam -- had chosen to paint the coast of Maine before Homer took it as his theme.

But Lane addressed the sea as a place of useful commerce, an avenue for ships. Last year's Hassam show at the National Museum, "An Island Garden Revisited," showed us that that painter loved the resort life there for its flowers and its musicales and parlor conversations, not for its stormy dramas. Though Homer planted flowers too, though servants served his luncheons, you'd never guess it from his pictures.

Noble and compelling (if somewhat antisocial), they are also far more studied than they at first appear. The powerful diagonals that so enhance their dramas suggest practiced graphic gifts and intense consideration. Their carefully tuned colors may at first suggest a scene captured on the spot, but they actually result from minute calculations. Consider, for example, "The West Wind" (1891), one treasure on display.

It looks astonishingly spontaneous, but it isn't really. Charles Lowell Homer, the painter's nephew, reminds us that the picture was painted on a bet. Homer, dining in New York with the painter John La Farge, had argued about color. La Farge complained that Homer used too many grays and browns, and that such muddy pictures would never be admired. Homer disagreed. They bet $100. After "The West Wind," which is mostly whites, tans and beiges, proved to be a hit, Homer wrote in triumph, " 'The West Wind' is brown. It is damned good! Send me your check for $100."

It takes a while to notice that Homer's points of view are often fiddled too. The diagonal brown cliffs that slice the National Museum's grand "High Cliff, Coast of Maine" (1894) are in actuality much lower and less steep. His watercolors often show a duck's-eye view of gunshots or a trout's-eye view of fishing. A number of these seascapes too suggest a gull's view of the waves.

But who cares if he exaggerated the menace of the ocean and the ruggedness of Maine? "Moby Dick" is after all not to be dismissed just because it's fiction.

Homer's forebears on both sides of his family were seafarers, he was born under a water sign and 10 times crossed the Gulf Stream. Water was his element. He knew his subject perfectly, as he knew his audience. His canvases are more than views, and much more than illustrations. It's not their scenes that one remembers as much as their passions. It's as if they were abstractions. None of Homer's countrymen, except perhaps Thomas Eakins, was so skillful with a brush, so technically proficient. And none, excluding perhaps Melville, understood as well as Homer did the shifting light and shifting shapes and intense symbolic power of the sea.

This little show also includes 13 works on paper, as well as vintage photographs of the bald and mustached artist that have been borrowed from Bowdoin College's Homer Family Collection. It is one of those rare painting shows that demands repeated visits. "Winslow Homer in the 1890s" will be the subject of an all-day symposium at the museum on March 23. The exhibition has already been seen in Rochester and Chicago. It will travel to Williamstown, Mass., after closing here on May 27.