I have always used Neutrogena face sunscreen too so I'm glad to hear that still works for you. I have been getting a bit of a butterfly rash on my face lately so I certainly don't want to irritate that! My doctor said it's ok for me to be in the pool for a little while with a rash guard and lots of sunscreen of course, but she didn't say anything about needing to wear leggings?? She just said I needed to be completely covered when poolside. I was hoping that the sunscreen and my legs being under water would be enough since I can't be in the heat or sun for very long at one time anyway. I hope I'm not wrong and learn the hard way, but I'm much more worried about the parks!
The water provides little protection from the sun; you can sunburn underwater. see:
https://www.sciencefocus.com/the-human-body/can-you-get-sunburnt-underwater/
For me, quality UPF 50+ swim tights is the way to go as I don't have to put sunscreen on covered areas [which I react to anyway, and which needs reapplying regularly, especially when playing in water] and they work in the water and on the pool deck/beach. Coolibar has a whole selection of swim tights (
https://www.coolibar.com/search/?q=swim+tights ), I'm sure other companies do too. I suggest full-length ones that go well to the ankle so you have full coverage.
Also think of your feet. I wear a good watershoe - I have
Crocs swiftwater but they no longer make the style I have. Lands End and others make nice full-coverage water shoes with good soles, eg
https://www.landsend.com/products/womens-slip-on-water-shoes/id_343106?attributes=7223
If you really want to go all out, a pair of swim socks - actually, they are thin fin socks normally worn by people wearing snorkelling or scuba fins. I got a pair of Deep See Lycra Fin Socks from
Amazon. Made of Lycra, seams not in uncomfortable places, and since I am wearing them inside water shoes, I do not need "no slip" grips, which these ones don't have. There are other brands. A local scuba shop can probably help you too if you want to see some up close before buying. They aren't UPF rated, but are basically swimsuit material and seemed to give a decent barrier.
One problem I have is that my face is really sensitive to sunscreen. Even the best of the mineral-only sunblocks (Vanicream; Blue Lizard sensitive) cause me issues on a bad day or if left on too long or when exposed to the sun (!!) on a good day. So I REALLY try the "cover up" method first, leaving sunscreen as my last resort.
One of the solutions I have is this hat from Coolibar. I will often wear it in the pool when I am going to be keeping my head above water [I have dunked my head with it, but I'm talking about when I am going to putter around or do laps with my head out of the water]. I have a previous version of it that is a little bit different, but it is basically the same. Mine is in white.
https://www.coolibar.com/uv-swimwea...hlorine-resistant-ultra-sport-hat-upf-50.html I will also wear it out of the pool and sometimes in the parks. It can get hot underneat as the fabric is not as breathable as say the Aire fabric. But it is easy enough to open slightly to adjust temperature. A nice thing is the front 'veil' peice can be worn across or not, so you have versatility. It gives great coverage in the back for your neck. In the pool this fully deployed with a pair of sunglasses gives you quite good coverage - just be cognizant that sun will bounce up off the water at your face so any still exposed skin does still need sunscreen. I've even worn it over a scully cap (
https://www.coolibar.com/uv-swimwea...m-hats/unisex-aqua-sun-skully-cap-upf-50.html ) and that combo, with wrap around sunglasses, while hot, pretty much covered everything [I was desperate and couldn't use sunscreen on my face that day].
For poolside, Coolibar makes a couple different shawls that are taller than me and wide enough that they make a nice blanket for laying over me when lounging. Made of their Aire fabric, they are lightweight and really easy to pack, and versatile so I can actually use them as a shawl/wrap too

I will drape it over me on the lounger and get both an added layer of sun protection and also I find I am cooler under it as it will catch a bit of a breeze and is not as heavy as a towel. It will also block the breeze a bit if I wrap it a bit on the sides [think cocoon]. Check the dimensions as they have a few different styles which have different length and width combos. They also have heavier-weight baby blankets that can work, but they are not as large.
Now, if you really want to get adventurous, I have some Sunsnapz UPF 50+ blankets and on one of our cruises, at
Castaway Cay I made basically a little fort out of my lounger that I relaxed under for hours. I also used a Coolibar aire fabric shawl directly over me. It was AMAZING !!
Some pictures of the "tent". In some you can see the shawl on the lounger:
SW