Greater & Lesser Yellowlegs 

Yes you are right.

Hard to tell apart unless they are together. Best way is if the bill is longer than the head it should be a greater.

I'm a novice at general water bird identification, although I'm not bad at identifying the shorebirds seen in Laguna Beach. There are quite a few, including oystercatchers, which are not common at all except in marine environments. Many of the other shorebirds I regularly see can also be seen in fresh water environments, particularly those with bills long enough to penetrate a ways into mud.