It all depends upon the depth of water. In the deep ocean you probably would notice nothing at all but as a wave, whatever causes it, crosses the continental shelf and enters shallower waters the wave becomes much shorter and steeper and, thus, far more likely to cause damage. So, in answer to your question, if you are in deep water off the continental shelf there should be no problems at all. In deep water on the continental shelf, say in 200 metres you will be alright but the wave will become more noticeable. Where you don't want to be is in shallow water.
I hope this answers your query. If not, you will find a very good (much better than mine) explination here
Aye // Stephen