For snorkeling from shore head to
Boca Catalina and Catalina Cove. It is easy to get to, just follow the "beach road" up past the high rise resorts and it is on the left hand side.
The easiest way to know you are in the right area of Catalina Cove is where there is an "L" shaped bend in the road. Here is a
video of the area for reference.
Unless you are very skilled, and athletic, the entry at Catalina Cove is
difficult, though doable. The entry here is extremely rock. If there are any
waves at all, it will be that much more of a challenge.
We have found it
much easier to enter the water at the small beach at Boca Catalina. Park here
and enter the water from the beach Just off the beach there will be some
juvenile fish. From here swim north towards Catalina Cove.
The visibility may not be very good between the entry and the point towards the cove where you begin seeing coral and rocks rather than just sandy bottom.
Go in the morning when the winds and current are less and you can spend as little or as much time as you wish in this location.
Just as a safety precaution if you enter the water at the beach at Boca Catalina, swimming north a bit and turn around and swim back to your original entry. This is to test the current. This will allow you to judge how difficult your swim will be. You don't want to have to swim north and then walk the hot dusty road back to your car at Boca Catalina.
From my review for Catalina Cove at
shorediving.com
"We snorkeled at this spot early in January. Entry is extremely difficult. There are nothing but rocks and the water is extremely shallow for quite a ways out. Once you get out, there are plenty of fish and critters to see. A much better option though is to enter just slightly farther south at Boca Catalina where there is a nice white sand beach and then simply swim along the rocky coastline towards the north."
The visibility may not be very good between the entry and the point towards the cove where you begin seeing coral and rocks rather than just sandy bottom.