Broke the bottom floating rib about 10 years ago when some idiot knocked the end of the weight when I was doing a heavy bench press. Took over 6 months to heal and I still have a dent in it - I agree with Bowski if it is really broken, then you won't even be thinking about getting on the water for 6 weeks, so you might be lucky and it is just bruised. When it breaks, it sounds like a dry branch snapping.
Simple test - try doing some push ups - if it hurts, then don't go out, next time you might break them and then you will be waiting to next spring before getting out. Get well soon