As you level, you'll encounter several quests that require you to swim so it's something you should learn. The spell is useful, but you should be able to reach the totem with regular swimming. Go out to the area where the totem is and practice moving in the water using your mouse. You should be able to learn to dive and to come up for air. The mouse movement is similar to looking up and down when you aren't swimming. When you dive, you'll see a bar that shows your "breath". Don't let it run out or you'll take damage and die.
In Chinese: glasses are yanjing; eyes are yanjing, and the beer of Beijing is Yanjing. When speaking, the difference is in the tones. Did I just order a glass of beer or a glass of eyes?