Sometimes the calm waters give way to south shore swells. For various weather reasons such as storms many miles out at sea the south shores of Maui will experience waves for surfing. As you have already seen the water can be very placid which is definitely better snorkeling conditions. However when the waves come up, locals from the island of Maui manage to always find the waves. Sometimes with the tide coming in at the same time the south shores are experiencing a swell, the waves can actually be pretty good. Near the harbor mouth is the "freight train". Supposedly the curl on that wave is one of the fastest around and challenges the better surfers. It makes for some very interesting sites as you sit by the pool. The surfers will actually surf right up till dark and the backdrop of the lights coming on in Kihei along the shore, the sunset, and the surfers makes for some spectacular sites.