Sea lions and seals love to bask and sleep aboard the floating ocean platforms, and are also known to frequent Dana Point Harbor and nearby Newport Beach Harbor. The poor critters are considered pests by boat owners who often are plagued with them trying to move on board a moored boat and take over. If you see orange netting on a vessel, it often is there to try to keep the seals and sea lions off.
The noisy, barking mammals can travel quite a distance and Dana Harbor isn't necessarily their home. The reason they've taken up residence in such places, however, is because they've discovered a food source.
When you take the excursions and whale watching cruises, have your camera or phone ready to snap a shot. They are normally waiting on cue for you (just kidding)