演 ＝ 氵+ 寅 but what's it got to do with water!? How did it get its modern meanings?
http://dict.shufaji.com/word-2326.html

甲骨文（水，喻流程）（矢，代军事操练），造字本义：古代军事模拟实战的流程式操练。篆文将甲骨文的“矢”写成“寅”，明确了军事操练的含义。隶书将篆文的成。

the 氵also got another meaning of flow (process flow), so it does mean that process flor for traditional battle(war) training.