Can someone explain why these shots are in focus as opposed to the 'ghost' and blurred figures in other shots of people just walking by?

[This glass plate was exposed for a split second to stop the action; in other cases, longer exposures were used because of dim light, or to use a smaller lens aperture in order to achieve sharper focus over a greater range of distance. By this time, photographic emulsions were sensitive enough that long exposures were not necessary just to get an image in daylight. -tterrace]

Everyone is posed so nicely in the other shot - then the splash happens!

Wow, surprised it took 15 comments to point out the lack of fat people on the beach 100 years ago. Slow day at Shorpy!

I'm more interested in the people out in the boat. Looks kinda dangerous out there!

What ever became of this couple? So rare to see such an intimate moment from that time.

Contrast this photo with the overweight people you would see at the same beach today.

I like beach scenes like this. Most of the ones I have seen had people in it that looked as if they were waiting in line at the DMV.

Love the woman with the parasol far in the back of the crowd. In water up to her shoulders, but we must keep that parasol high and proud.

Impromtu and unposed, smiles and laughing rarely seen in vintage pics and even the sun's glint off the water make me think this could have been taken yesterday if it were not for the swimsuits...

One person standing with umbrella in the back !
Always good too see so many people having fun, great picture !

Wow. This is the first time I have ever seen a picture from this era with literally EVERYONE smiling! It makes the photo seem all the more timeless. Awesome.

Love the solitary figure, fairly out into the water, with an umbrella. That's a pretty tricky device to walk about with in active surf currents. All in all, a very happy and jovial group.

The lady is about to get her sunscreen washed away.

is standing in front to the left.

What a pleasant picture. It seems so odd to see so many people smiling. Except for their suits, they don't look that different from modern folks. The lady holding an umbrella far out in the water is an odd sight, though it may not have been back then.

Some of the young couples in this photo are touching each other in public. One couple is even holding hands!! Where's the morality police when you need them??

It's rare to see so many spontaneous, unguarded smiling faces at once in such an old photo. I love it.

This is one of the few Shorpy photos from this era where most of the folks are smiling and appear to be having a lot of fun.

I see Tina Fey's grandmother in the front left, about to pounce on someone.

And what's with the guy with the umbrella, out in the deeper waters?

Too many people in too small of a water area creates the image of some type of tepid human broth. There's a whole ocean and entire shoreline out there, so why is everybody clustered in the same small space? It would be like someone getting on a bus containing only the driver and one passenger and the newcomer sitting down to share a seat with that one passenger. (Yes, it did happen to me).