There I was, in one of my favorite local spots: swell moderate, vis. good... I had been waiting for days. Yet, after no more than 45 min. of diving I began to get sea sick. Symptoms: nausia, dizziness, general feeling of weakness stemming from the two. I'm fairly new to the sport, but this is only the second time that this has happened in about 12 dives. Both times were caused by rocking in mildly turbulent water as I was catching my breath and both times I ended up having to leave the water early and lay on the beach as if deeply hung-over. Why does this happen and, more importantly, what can I do to prevent it in the future?