The most annoying thing in gaming is when someone coasts.
Tips
culture
划水 originally comes from competitive swimming — paddling gently just to stay afloat rather than racing hard. It became popular in gaming communities to describe teammates who contribute nothing, then spread to work and school contexts.
usage
Similar to 摸鱼 but with a slightly different nuance: 摸鱼 emphasizes secretly doing personal stuff, while 划水 emphasizes putting in minimal effort while appearing to participate.