Dolphins?

We live one block from a large beautiful bay. In our neighborhood, there is a tiny beach on the bay. We often walk to the beach to watch the sunset and sailboats; it is just so beautiful. Sometimes, we even see dolphins!

About a month ago, we bought some highly rated inflatable kayaks. We are here only one more year and decided spending the money on two pvc two-person kayaks was too expensive, but renting each weekend was also getting expensive. I calculated that if our inflatable kayaks last six times they will more than pay for themselves. More than that is simply cake.

We take our kayaks to our little beach one day each weekend. Last weekend was no different. We got all set-up and as we were putting our boats in the water, we saw two dolphins, or at least we assumed they were dolphins. They swam far ahead pretty quicky, never jumping out of the water. They appeared to work together to corral the fish, each coming in at a 45 degree angle from each other. This was followed by a big commotion in the water, then by a huge flock of birds settling on that area of water. We turned off before reaching that area. 

As we talked more and more, we thought the fins were not actually bent like dolphin fins, though maybe they were? We never saw the animals jump out of the water. And, they actually swam rather straight and fast. Apparently, sometimes smaller bull sharks make their way into our bay. Now, we are wondering???