As indicated at the beginning of last season and reiterated several times this winter, the rules for approved bats changed before the 2018 season. This is a multi-league, nation-wide transition, not just West Seattle Baseball. The new bat rules are aimed at creating a more wood-like performance. A notable change is that with the new rules, big barrel bats (2 5/8") will be allowed in all divisions now. These rules will be strictly enforced this upcoming season in game and practices in order to protect the integrity of the game. Only bats that bear the USA Baseball licensing stamp will be permissible for play in any West Seattle Baseball activity (including practices).
While it's not easy to tell everyone they must spend more money, we have investigated and found several affordable models. If you haven't already purchased a bat there are websites and local retailers such as Dick's where you find these legal bats. Also, here's a link to a 20% off Dick's coupon for the weekend of 3/9-10 if you're shopping there.
If you have questions, please refer to this FAQ document as it will provide you with all the answers a lot faster and with more detail than contacting the WSBB Board. Included in the document is a link of approved bats.