We will be crusin April 9th out of San Fran going to Mexican Riveria..How wam is the water then?
All of the ports of call along the Mexican Riviera are in the tropics, so the water temperature usually is pretty warm -- perfect for swimming.
That said, there's an aberration called la nina -- a pocket of abnormally cold water in the Pacific Ocean. Apparently as a result, the water was much cooler than usual (probably upper 60's) in Cabo San Lucas, Mazatlan, and Puerto Vallarta about four weeks ago. It was fine once you got into it, but definitely not the much nicer "bath water" that we encountered the following week in Manzanillo and further south. AFAIK, la nina is still there.