Account Level 15
Total number of battles needed to reach this level: 200
Becomes available:
Clan Battles
Training Rooms
In order to experience the challenge of Clan Battles, a clan member must first attain Account Level 15. Level 15 members have the ability to join their clan on the battlefield, queuing up as a group to challenge others on their server's Clan Rating leader boards. Also at Level 15, a player may begin to use Training Rooms to hone his skills.
https://wiki.wargaming.net/en/Ship:Account_Level