I'm doing the cake for my step-daughter's birthday in a couple of weeks, but I'm a bit worried - she wants a beach party, which means I'll have to bring the cake and keep it from melting until it's cake time (probably after games and swimming and such).  I could try to push for cake to be The First Thing, but it would probably still be sitting for some time while we set up and wait for latecomers.

Do you have any suggestions to keep the cake from melting while we're at the beach?  Could I keep it in a cooler with some ice packs?  Should I keep it in the car or try to find a shady spot to store it?

I'm willing to alter the dimensions, type of buttercream, use of fondant, etc. for improved stability. :)

I did a cake for an outdoor wedding in North Florida in the 90 degree heat last weekend. It also rained! Luckily they had it placed on a table underneath a tent they had set up. It was under the shade and I made my buttercream with a 50/50 shortening ratio to help with stability. The frosting was very soft when I went to cut it but the cake remained completely intact the only issue was the fondant was very shiny from all the humidity. The cake sat out there for about 2 hours until it was cut.

Thanks, pag41989.  I'll try using a 50/50 ratio buttercream to help a bit with stability, and also keep it in the fridge until we have to leave.  Hopefully we'll be able to find some shade to store it in.... that's good to know that yours lasted a couple of hours at least!