When thinking of whale watching in and around San Diego you should really consider greater Southern California.  Many providers offer whale watching only during the traditional whale watching season which is from January thru April, however; there are several whale watching providers that provide whale watching year round.   What you get from these year round providers may be worth the extra travel time and that is up to each individual.  The perks of these year round providers are ships designed specially for whale watching, highly trained staff, and a more focused experience.   Here are several year round whale watching providers:

Newport Landing Whale Watching-  $16 Whale Watch Special They are located in Newport Harbor about 1 hour 25 mins from San Diego. With a 96% success rate they take their whale watching very seriously. Grey whales in the winter/spring and giant blue whales in the summer/fall.

Condor Cruises-They are located in Santa Barbara which is about 3 hours from San Diego.  They travel to the famous Channel Islands and also have a high success rate with viewings. Their website is http://www.condorcruises.com/ . Sightings can include grey whales, blue whales, humpback whales, and others.

San Diego has year-round whale watching providers: Adventure Rib Rides is a high-speed wild ride on a former Navy Seals attack boat. Or you can rent your own boat with Seaforth Boat Rental .

San Diego also has seasonal whale watching providers such as:

Point Loma Sportfishing - http://www.pointlomasportfishing.com/

Hornblower Cruises- http://www.hornblower.com/

H&M Landing - https://www.hmlanding.com/

Also in San Diego, there are several choices for whale watching from a sailboat:

Classic yacht JADA can be chartered for any occasion year-round or you may join her on one of her regularly scheduled outings during the winter season.

Replica yacht America, from December  through to April.  They also do blue whale excursions during the summer months. Four hours of sailing start at $85/person with a no-seasickness guarantee and free admisson to the San Diego Maritime Museum, a $14 value.

 For those considering shore bound whale watching a great shore based location is the Cabrillo National Monument.  The cost to enter the park is $5 per vehicle.  The Cabrillo National Monument is the birth place of whale watching and still provides good opportunities to see grey whales.  Make sure to bring your binoculars. 

When selecting a day to go whale watching try to pick days with light winds or if strong winds are forcasted select morning or early afternoon options.  Choppy conditions can make it harder to spot whales and less comfortable for those onbaord.  Worried about motion sickness ask ahead of time what the sea conditions will be like.