There were indeed a few. Including one poor soul who at the NOAB decided he wanted to be MARS instead of CSE. Losing his (at the time) $40,000 signing bonus in the proceed. And then later flunked out of MARS training, and eventually became a CSE, making Lt(N) a good 3 years after the rest of us.
Anyways, unless you're extremely motion sick, you're not going to get sea-sick on a day sail in the Straits of Georgia. Not enough motion to the ocean. And if you would get sick then... well, might I suggest the Army?