Sport Chalet Inc. this weekend will hold grand opening ceremonies for its newest store in Thousand Oaks. The 40,000-square-foot store will feature an on-site SCUBA training pool, slated to open later this summer. It is the 41st store for La Canada-based Sport Chalet, a specialty retailer that targets sports enthusiasts from hikers to golfers. The opening ceremonies, which will take place over the Memorial Day weekend, will include an extreme sports exhibition, and personal appearances by heavyweight boxing champion James Toney and the SPLIT surf team, among others.