I don’t think a theme is necessary. The children will have a fantastic time regardless.

I think the children will be excited just to attend a pool party.

It’s at the pool, I would think that was exciting enough and wouldn’t need any extra excitement added by making it themed. Pool/beach they’re both water themes, I don’t think the kids will mind beach stuff in their party bags

I guess just about anything water themed could get included in a party bag for a pool party. I don’t think the kids will stress too much, they’ll be too busy enjoying the pool party

$2 shops have lots of party pool toys that you can buy. Like water guns and floating toys, blow up balls etc. they are cheap and you can give them out as party bags instead of lolly bags.

it is up to you but i just had an idea! get those bundt cake pans and make a life preserver floatie ring cake lol

I like a themed party but understand that to get exactly what you want can get pricey. Have you tried pininterst?

Themes are fun and you can get lots of great ideas for cheap or free games, food and decorations from Pinterest. I have attached a photo taken from Pinterest that I used for my nautical themed baby shower

Thank you everyone for your help.
Re one of the answers, its at the local swimming pool centre so unable to do all those things.

I think BUGGERITLIZ HAS ALL THE ANSWERS OU NEED! Check out her answer!

Ask your boy if he wants a theme. If he does, go to one of the junk stores, because you can generally pick up stuff really cheap to make it a brilliant theme party.

Your theme can be anything you like, just because your going to a pool doesntmean it needs to be pool themed, maybe ask your son what he would like?

Sounds wonderful; I would go to a cheap trinket shop and see what novelties they have around pool/water themes and then decide on your pool/water theme.

You could go to the reject shop and buy every child a blow-up pool ball and ring.
They could then take their’s home instead of a lolly-bags. Whilst you are their get a couple of pool games.. like things that they have to dive down and retrieve. There could be lucky dip prizes for games.. put these in buckets. How about water-balloon pinata. Play Invisible Bottle – Take an empty clear 2 litre plastic water bottle. One with a white cap, or the same colour as your pool tiles. Fill the bottle with pool water and line the players up, backs to the water. When they hear the splash they can turn around and try to find it. They have to jump in and get it. It’s harder than it seems as the bottle camouflages to the bottom. Another games is treasure hunt. Throw a hand full of money into the pool. They all jump in and the one with the most money… wins it all!
My daughter came home from a backyard pool party with a cheap beachbag, a pair of $0.99 thongs a pool noodle. I thought WOW! She loved this and she still talks about it, 15 years on….

You could still do beachy as that is pretty close.
I love a themed party and it will be more memorable for your child in years to come.
I always remember when I had my pink and purple party as a child the others tend to blur in together.