The last week or so has been a great time for openers, with the Red Sox, NHL and NBA playoffs, "All the President's Men," eye and can openers all occurring within a relatively short space of time.

Tomorrow, however, has been reserved for perhaps the most significant of all the April openers, for tomorrow, in case you don't know, is opening day for the 1976 trout-fishing season in Massachusetts.

Standing-room-only crowds are expected throughout the rivers, lakes, and brooks of the Bay State; tickets for this event have been sold out since the first freezing of the inland waterways last winter.

Here at Harvard, the 15 or so Hemingwayesquerough riders who comprise the active membership of the Harvard Fly-Fishing Club, an organization with its own charter and constitution, have been anticipating this day with an eagerness comparable to that of Captain Ahab when he spied his albine leviathan.

Or at least that's what Geordie Thomson, the Ahab of the Crimson fly-fishermen, said the other night while practicing his casting out of his eight-floor Mather House window.

Thomson, who says that he's universally known as the founder, organized the fly-fishing club in 1973, and served as its president for two years. While Neil Malone and Chris Lefarge currently hold the presidential titles, Thomson still maintains that "I'm the captain of the team."

The club was founded on two principles--first, a dedication to making the members of the club the best fly-fishermen possible ("Fly-fishermen are the best people in the world," Thomson says,) and second, as an endeavor to instill within the group a love of conservation.

In reference to this latter principle, the club works with the Greater Boston Chapter of Trout Unlimited, the foremost water conservation group in New England, on its Stonybrook River project in Weston, Mass.

"We want to create a natural habitat," Thomson explained while tying flies, "which will hold fish by keeping the water clean and oxygenated, and by providing care and food for the fish."

As for the initial purpose of the club--becoming the best rod wielders since Queequeg and Tashtego--Thomson says, "We're appealing to those who feel that they have time for fly-fishing. We don't feel obliged to teach unless you have a real commitment."

In addition to the 15 hard-core members of the club, there are about 40 interested individuals who desire to do battle with the brook, rainbow and brown trout encountered in the New England waterways.

"I've been fishing for four years," Thomson said. "I was given a fly rod as a high school graduation present. I took off, and I loved it."

This weekend, Thomson will be taking off to one of his favorite fly-fishing hide-a-ways, whose location he refuses to disclose. For Thomson, and other fly-fishing fanatics, this is not just another opener, but an entirely different can of worms.