I vigorously maintain that babies are far lower maintenance in warmer weather.
So, when packing for vacation, you get to pare down to just the essentials. A couple of cute onesies, a romper, some swimsuits, a hat and a whole lot of sunscreen.
bloomers. There is nothing cuter than baby bloomers.
A note about the sunscreen wipes. I love love love the MD Moms Babysilk Sunscreen Wipes in SPF 30. They smell heavenly, can be wiped on a squirmy baby, and don't spill in the diaper bag. However, they are officially not cheap. Since you should be using sunscreen on your baby at all times, I supplement with Aveeno Baby Sunscreen. Which reminds me I need to place a massive sunscreen order at Diapers.com...