He began shooting at age seven, thanks to his father, at the Celoron Rod and Gun Club and during the 1960s, claimed the county's junior skeet championship and the trap and skeet title as an adult. He also won numerous club and leagues championships, including the New York-Penn League. After Whalen's victories in 1977, his father converted to trap shooting and his son followed in his footsteps and the pair won the Eastern Zone Singles Championship in both 1985 and 1986.
For the next 30 years, Whalen's abilities produced dozens of local, state and regional titles in both doubles and singles competition, right up to today, including six Eastern Zone championships and two runnerup finishes. In the Eastern Zone competition in 2005, Whalen was engaged in a sudden-death shootoff and hit 574 of 575 targets, which established the record for the longest consecutive shootoff in Eastern Zone history. In fact, one of the three competitors in this event, who was unable to finish, was the reigning Clay Target champion of North America. He also was a Northeastern Zone two-man team champion in 1993, a Northeast Grand Class winner in 1997
Whalen was a New York State doubles champion in 1983, 1993 and 1997 and won the singles AA crown in 1983, 1986 and 1990. He also took the Pennsylvania Grand Doubles championship in 1983, the Pennsylvania State Shoot AA singles crown in 2001 and PA Shoot Handicap title in 2005. Whalen also picked up four Zippo championships in 2003, 2004 and 2006. Up until 2004, Whalen was the only person to have ever held both the New York State skeet championship and the state trap championship titles.
Whalen and his wife, Bonnie, also earned the state AAA resident runnerup high all-round honor and the state husband and wife shooting championship in 2006. In 2005, he was recognized for achieving a competition level called AA-27-AA. In order to receive this honor, a trap shooter must have an average of 98 percent in singles and 96 in doubles. This special award is both prestigious and extremely difficult to attain.
Whalen has been a member of the American Trap Association since 1979 and was named a lifetime member since 1984 and is currently the New York State delegate to the ATA national board of directors. He has been the president of the Penn-York Trap League in 2006 and 2007 and is the longest living member of the Celoron Rod and Gun Club and has held its presidency since 2003. He is also a member of War Vets Recreation, the National Rifle Association and a past member of the Falconer Rod and Gun Club. Whalen has been an instructor, coach and sponsor of the Maple Grove Youth Junior and Senior High Trap Club and has been a volunteer instructor for BOCES Criminal Justice class in firearm safety and trap shooting.