We just spent two months in Maine and after enduring many, many rainy days, we finally enjoyed some beautiful beach days. Our ten month old grandson LOVED the sand and the sea.
We set up a beach cabana each day and put his pack 'n play in it. We also managed to fit two beach chairs (one on each side of the pack 'n play) just inside the cabana, enough for some partial shade for others. The idea was for Carter to nap in it, but he had other ideas.

A three month old, however, would probably nap just fine in it. It was perfect for changing his diaper and sitting him in it for a snack, but he preferred napping in his stroller.
Here are a few pics so you can see what it looked like. It's kind of in the background because I was more interested in taking shots of Carter and not the cabana, of course!
Here he is, sleeping in his stroller. I put a beach towel over the top of the stroller's hood to give him more shade. He was quite content!
A hat is also an absolute must! I love this one because the flaps protected Carter's ears and the back of his neck as well as his head. He had a similar one when he was around two months old, so I know they make them for very young babies as well as older ones.
Enjoy your beach vacation! If I'm remembering correctly, you're heading up to my hometown in Maine. Have a wonderful time!!
