Cruising Norway's fjords: let me count the ways

When summer's heat seems to stretch from Penobscot all the way to Pismo Beach , the thing to do is take off for the fjord country of Norway, where the sun shines until midnight but the outdoors is eternally air-conditioned.

There are a number of ways to embrace the western fjords - hiking, driving, riding buses and trains - but to get the real essence of these bottle-green bays , it's wise to travel by boat. High summer brings a whole parade of cruise ships up the craggy 1,000-mile coast, but lately some smaller, more economical craft have nosed into the business, capable of exploring shallower, more remote waters the leviathans can't touch.

One such way is by coastal steamer, the beloved hurtigruten, meaning speedy route, although it is anything but. This fleet of vessels has historically plied the fjords in January as well as July, but this year for a change a summer berth is more easily booked. Scandinavian Airlines and Bergen Line Inc. are together signing up passengers into October and tacking on optional side trips by bus, shore excursions to the North Cape, and dinners at fjordside hotels. (For more information, write to Scandinavian Airlines, Box NCV, 138-02 Queens Boulevard, Jamaica, N.Y. 11435.)

There is nothing sleek or artificial about these hardy steamers, which carry food, furniture, mail, and tons of fresh fish between the remote coastal and island villages and can berth as many as 500 passengers. There are 13 craft in the five-company consortium, and one leaves Bergen every day on the 11-day round trip. Even if you don't book a full cruise, or even a partial one, you can always buy a ticket, come aboard as a day-tripper, and hop off at the next port. There are 30 ports of call, and each treats the arriving steamer like a long-missing relative. Townsfolk crowd the harbor, mail and other cargo are dropped off, and a band strikes up a farewell blast.

Even when it rains, passengers can be found on deck glorying in the passing post-card scenes: waterfalls tumbling from snowcapped mountains, trim, tiny farmhouses standing aloof in lush meadows or at the edge of steep fjords.

Another cozy way to see the fjords is aboard the North Star, a so-called yacht cruiser that carries 155 passengers. At 3,000 tons it's a rowboat compared with the QE2, the Royal Viking Sky, and other coastal visitors. The North Star is a converted trawler that was built in 1966 and redone in 1982 when it began an abbreviated schedule on the fjords. This summer it's sailing full-time, after having done the Suez Canal and the East African coast over the winter.

One of its attractions is the ability to penetrate the fjords more deeply than the big liners. Another selling point is its relative economy. There are six- and seven-day cruises out of Gothenburg, Sweden, beginning at $835 per person for a double room. The ports, all inviting, mostly remote, are Olden, Flam, Gudvangen, Bergen, Ulvik, and Eidfjord.

Less pricey than the North Star is the Funchal, built in Denmark, renovated in Holland, and owned by the Portuguese government. It's three times the size of the North Star, but carries just 385 passengers. (Either boat can be booked with Scandinavian Airlines at the above address.)

If you want a lovely, roundabout route to the western fjords from Oslo, I can advise a smorgasbord of transportation that includes train, fjord steamer, and bus. Four times a day a cross-country train leaves Oslo for Bergen, climbing into central Norway, where summer seems to turn to winter and glacial slopes replace green valleys.

At Myrdal, two-thirds of the way to Bergen, a rail spur leads to the fjordside village of Flam. This side trip of 12 miles and 45 minutes is one detour worth taking. On the slow, spectacular climb the conductor twice halts the little train so passengers can jump down to snap photos or simply gawk. The first stop is high above a green valley floor sliced by shining streams; the second, beside a waterfall that rumbles down in four stages to within spattering distance of the track.

Flam has a commodious little wood-frame hotel, the Fretheim, where I once passed an almost shadowless summer night. In the morning, if you are going on to Bergen, you hop a fjord steamer almost in the hotel's front yard. Then in mid-fjord the Bergen-bound travelers step onto another steamer that pulls alongside. As they sail away, the two toot each other goodbye.

From there it's a lovely watery run to Gudvangen; a bus to Voss, where a statue commemorates a favorite son, the one-time Notre Dame football coach Knute Rockne; and a reunion with the cross-country Oslo-Bergen express train. Bergen, which some liken to San Francisco, Seattle, or Vancouver, is the western gateway to the fjords. In midsummer it stays light until 10 or 11 at night, but if it's the eternal sun you want, you have to venture above the Artic Circle, where the sun refuses to drop below the horizon from May until late July. Such conditions do not promote sleep, but be assured the air conditioning will be on ''high'' all summer.