Bummer, we left PBSB on the 14th, too! I guess I should have checked TUG instead of just my e-mail while I was there ...
But to answer the question about whales: we saw tons of them from our balcony, usually at mid-morning. We also went whale watching with Cabo Expeditions, using the 2-for-1 coupon that is on the PBSB homepage. Some caveats about the outfit: they use zodiacs seating 28. If they have a full load, which we did, it is very close seating, and no backrests. You will also get splashed if you sit in front, as I did (it was kind of embarrasing walking around with wet pants afterwards ...). It also gets cold, especially if you are drenched. As for the whales: we saw more whales from our balcony than we did on the trip. We also saw many boats watching the whales that were offshore from PBSB, the Buccaneer Queen among them. If I were to do it again, I would go on the Buccaneer Queen.