Toy for airplane. Finger foods and lots of milk. Extra outfits n blanket incase of a mess and cold airplane. Baby carrier. Stroller. Hat.sunglasses.swim suits n diapers. Sunscreen. Beach bag n towels. Baby tylenol n motrin. Lotion. Thermometer. Bug repellent. Beach blanket or sheet. Passports. Camera. Cell phone chargers. Look up local hospital phone number address etc-if u have them u will not need them. Sippy cups n bottles etc. This is all I can think of. Have fun!!
Same here we are going to Barbados with a 6 hour flight (Yikes!) so I'm just starting to get list ready. Does your LO need a passport for Costa Rica? I'd double check we do so I have made an appointment with the passport people. But I'm packing new books/new toys, tons of snacks and quiet treats. We are also bringing our portable dvd player so LO can watch and be distracted for alittle while haha.
Re: beach vacation packing list?
Here is one off pinterest
https://www.smartertravel.com/blogs/today-in-travel/the-essential-beach-packing-list.html?id=5286486
The whole blog post is about beach vacation packing, but the list is there, just thought it might all be useful to you.