The young and talented Harvard swimming team, its chances of finishing among the top three in the Eastern League problematical but possible, begins the second year of coach Don Gambril's much publicized rebuilding program this afternoon at 3:30 p.m. when it hosts a mediocre Navy squad in the IAB.

The Midshipmen extended the Crimson to the final freestyle relay last year in Annapolis before succumbing 57-56, but have been decimated by graduation and, as a result, do not pose as serious a threat today. A dearth of outstanding freshmen seems to indicate that the Naval Academy is losing ground to the other Eastern swimming powers, largely because of its inability to keep pace in the recruiting derby now being waged by the Ivy colleges.

Harvard, on the other hand, is holding its own in the battle for outstanding swimmers, and this year's team, the youngest in Crimson history, may also be the best and the most talented. Don Gambril's low-keyed program appears to be taking hold and morale, always a trouble spot in the past, is extremely good this fall.

The Crimson's outstanding strength is in the middle and distance freestyles where a strong nucleus returns from last year's highly successful 6-3 year. Sophomore Rich Baughman, who holds University records in the 500, 1000, and 1650 yd. events, will be pushed by freshman standout Hess Yntema.

Navy's top swimmer, sprinter Rex Hand, will meet Harvard's top 50 and 100-yd. threat Tim Neville in what will probably be the best matchup of the afternoon.

In the specialty strokes the Crimson will be stronger than last year when acute weaknesses in the butterfly and backstroke hurt considerably. Freshmen Yntema and John Craig will bolster the fly and frosh Tom Wolf is a threat to break the Harvard record in both back strokes. Sophomore star Dave Brumwell leads a strong Crimson contingent in the breast stroke.

The arrival of a top-flight diving coach, John Walker, and two time Eastern prop diving champion, freshman Dave English, may make the Crimson diving both more palatable to watch and more productive on the scoreboard. Junior John Zakotnik, who came on strong late last year, continues to improve rapidly and the English-Zakotnik combination may have the talent to sweep several meets.

"The Navy meet probably won't be quite as tough as last year," Gambril said yesterday. "We'll probably go easy," he added. In the back of Gambril's mind, however, are thoughts of an all-important January meet with Dartmouth, which, on the basis of a 73-40 lambasting of a powerhouse Princeton squad last week, may be the team to beat this winter. Last year the Big Green knocked off the formerly unbeaten Crimson, 57-56, and this year's meet may be a more valid indication of Harvard's strength than today's confrontation with Navy.