(FORTUNE Magazine) – ARCTIC ALASKA FISHERIES CORP. Traded on the American Exchange since April, this company may be the best way to buy into the lucrative Alaskan fishing business. Not so long ago the richly stocked waters of the Bering Sea and the Gulf of Alaska largely were the preserve of Japan's efficient trawlers, fitted out with on-board factories to skin, head, gut, bone, and freeze the catch. Domestic fishermen in conventional boats caught high-priced salmon and crab but couldn't compete in cod and pollack, the white-fleshed, bland-tasting species used in fast-food fish sandwiches and many frozen products. Since 1976 federal law has limited the catch in Alaskan coastal waters, giving U.S. boats first dibs. That encouraged American fishermen to invest in Japanese-style floating factories. This year, the first in which U.S. boats caught their full allotments, Francis Miller formed Arctic Alaska with 17 boats, America's largest such fleet, including the factory trawler Northwest Enterprise. Security analyst Andrew Brichant of Ladenburg Thalmann & Co. in New York expects the company's earnings to double to over $18 million this year on sales of $125 million.

TRIMEDYNE INC. Lasers aren't about to replace the scalpel as the standard tool in the operating room. But Trimedyne, which trades over the counter, has built a thriving business on laser probes that unblock hardened arteries in patients' legs. Inserted into the artery, the disposable probe uses fiber optics to carry a laser beam that vaporizes deposits of fatty cholesterol. Since the FDA approved this therapy last year, Trimedyne's product has treated some 7,000 of the four million Americans suffering from hardened arteries in the leg. The company is testing a similar product's effectiveness in blocked arteries to the heart. Analyst Frank Ingersoll of Knibbe Financial Group in San Antonio expects profits to increase more than 800% to $4.4 million this fiscal year on sales of $30 million. At its recent price of 24 times 1988 earnings, though, the stock has gotten expensive.

WELLMAN INC. Like it or not, the future is in plastic, since we can't seem to get rid of the stuff. Wellman transforms soda bottles into polyester fibers, which its customers turn into carpeting and linings for neckties. So far ten states, including California, have passed laws that encourage such recycling. Analyst John Stanley of Wertheim Schroder predicts that Wellman, traded over the counter, will earn $36 million this year on sales of $300 million.

ACTION AUTO RENTAL INC. This is not your standard rental agency. Working with car insurers, Action supplies rental cars mainly to policyholders who have wrecked their own vehicles or had them stolen. The rentals are inexpensive: $15 to $20 a day, about half what Hertz charges. Action's cars are mostly downscale models that are older than standard rentals; the company saves more money by parking them in the suburbs instead of costly airport sites. The third-largest company in this part of the business, Action is the fastest-growing. While the $8- billion-a-year car rental game has cruised along on 13% annual growth, Action's net income rose 60% to $2.9 million last year, and its sales went up 80% to $35 million. Analyst Charles Finnie of Alex. Brown & Sons in Baltimore expects Action, whose shares trade over the counter, to earn $5.5 million this year. He attributes much of the gain to increasing numbers of stolen vehicles and accidents. He also thinks raising speed limits to 65 mph in 40 states should be a boon for the business.