Well we ended up going to Port Aransas - it was soo pretty. Seaweed was definitely not an issue, there was some but a very narrow strip of it, not continuous and far back from the water. But we did encounter a LOT of jellyfish and saw two portuguese man o' wars (which btw are not jellyfish and you should not put vinegar on b/c it makes the sting worse). Two guys both touched a portuguese man of war (grr after I told them not to and why) and got small stings. The hubby got jellyfish or man o' war stung on his leg and chest/neck while in the water and got rashes out of that.
I was body boarding Monday night and while gliding along on a little wave the top of my foot went sliding across the top of something squishy. My foot swelled up some so I had to take my toe ring off. And then yesterday my other foot felt stingy and swollen too so I must have gotten some of the microscopic little stingers on it overnight. And then by rubbing my feet I got them on my hands

It wasn't awful, just a bit uncomfortable and stingy/rashy feeling.
But the man o wars are pretty scary b/c some people are allergic and can stop breathing so look out for those if you go - they have transparent bodies with blue tentacles.
http://en.wikipedia.org/wiki/Portuguese_Man_o'_War
The Port A water is very shallow for a long distance so very safe for kids. There are some waves that knocked them over once they were waist high but there are none of the huge waves that anyone would go surfing on. It's very silty water so you can't see your feet - a downside b/c you can't see if you're near an underwater jellyfish, or anything else. In the evening the fish would jump and skip along the waves - one theory is that they do that just for fun

It sure looked fun. The Port A beach is very very wide so tons of room for sand castle building and digging holes, running around. The surf goes in and out in a very satisfactory way. Water is more gray than blue so that's one downside if you've seen blue water before but it's beautiful in the evening

We went three times in the evening and that was my favorite time of the day to go - between 6pm and 9pm. The one time we went during the day (10am to noon) the hubby got super sun burned and was pretty miserable the rest of the trip. That was despite putting suntan lotion on him and not getting in the water during that time - guess he sweated it off? He was making a sandcastle with the little boys. He now has little blisters on his shoulders
We took one day to go to Corpus Christi and visit the Texas State Aquarium (be sure to catch a dolphin show - the 3pm was still pretty hot - not much shade) and USS Lexington (hubby's favorite part of the trip). We didn't go to the beach there (it's so much narrower than PA's and has tons of little crushed seashells in the sand and not as natural looking with all those tall buildings behind it) but rather beat it back to PA for an evening beach trip that day

But first I insisted on checking out Beach Access 3 (we were usually at zero). It was GORGEOUS with very few people and at that point you can drive right up to the water. But not planning to go right onto the beach or anything our low to the ground minivan got stuck just on the little access road where some sand had piled up

We got it out with a couple people helping us to push, putting our beach mats in front of the back tires, and good use of a sturdy little sand shovel to dig out the front tires hehe. But another family tried to go out onto the beach in their Suburban and got VERY buried. A Jeep had to come get them out. Only trucks with the giant monster tires were out on the actual beach. Despite the two big trucks on it, it looked a lot more beautiful/natural because there weren't the pylons blocking the beach from car traffic and all the cars parked behind them. But also no showers/portapotties like there are at Beach Access 0 (the northernmost one on Mustang Island).
We stayed at the Holiday Inn (two very short blocks from the beach but we still drove and parked) in a suite which I LOVED. We've stayed in the beachy style condos before and I prefer the clean modern hotel room look and free breakfast

It had a kitchenette (cabinets, drawers, mini fridge, microwave, sink, paper towels, coffee maker w/ coffee and tea) so I brought tons of food and we only ate out twice. Washer/dryer on each floor ($1 to dry, $2 to wash + $1 for detergent). Big fish tank in the lobby viewable from breakfast area too. All the boys slept in the living room (sofa bed and portable crib) so we got the bedroom to ourselves

Holiday Inn breakfast was 6 to 9:30am - boiled and scrambled eggs, bacon or sausage, three cereals, yogurts, biscuits w sausage gravy, three juices, tea, coffee (decaf too), milk (skim too), toast, butter, jellies, bagels, cinnamon rolls, oranges or bananas. The pool was gorgeous and very small kid friendly. There's a 6 inch depth baby pool with three little fountains, a bench seat that goes all around the main pool that our kids loved walking on - part of it backs to a fountain that is a mini waterfall into the pool, steps and shallow area are 3 feet so our 6yo could walk in that and 4yo almost could. There's also a hot tub. The pool/hot tub area is enclosed by the hotel on three sides - one side had a tall fence so was cozy

There's no water view from the hotel so you might want to ask for a pool view. And top floor if you can to avoid little feet jumping above you. It felt awesome getting in the pool after being at the beach. Beach parking is $4 but we never did pay for it b/c the one time we were there in the morning we didn't notice them parked there collecting money (oops) and they were never collecting in the evenings when we mostly went to the beach. One time we drove by just to see the beach on our way to Corpus and saw them parked.
I highly recommend the Pizzeria Port A, on the road between the ferry and Beach Access 0. They have a buffet between 11 and 2 and 5 and 9:30 - $6.50 for adults, children are 40 cents times their age, 3 and under eat free. Pizza, dessert pizza, salad, soup, pasta, soft serve ice cream. They make everything from scratch and you can tell - yummo!
Between 3:30 and 4 or so the fishing boats come back with tourists at the white sign that says "Dolphin Watch" (and at various other fishing charter places) and you can go see what they all caught - various fish and sharks - they measure and filet them. There's a candy shop we didn't get to that apparently has great home made fudge. And I was dying to go into a shop called Popsicle Toes that specializes in anklets and toe rings but they were closed the one time we went by for Father's Day.
On our way home we drove all along the bay and through the little downtowns of Rockport and Fulton - very pretty. It's neat to see the big beach houses on the water as well - some have canals in their back yards. Rockport's beach was a bit small and doesn't really have waves (some very very gentle small ones) but that would make it very toddler friendly. It's also the only certified "blue wave" beach in TX - so very very clean and water is clearer than most. There's a playground and some covered beach areas and a natural saltwater pool.
At Fulton on the way home yesterday we stopped at a restaurant called Charlotte Plummers that was recommended to us. We sat in their upstairs outdoor area which had a view of the Fulton Fishing Pier (free to walk on or $2 per pole), a playground (which includes a handicap swing), and lots and lots of cute boats parked

It was pricey compared to our usual fare (max entree was $20 or so but also lower priced items like pasta or cheeseburger) but did have a good kids menu ($5 average) - grilled cheese, fish and chips, etc. We then walked out to the end of the public pier and saw a dolphin jumping around and four kinds of jellyfish o.0 They were everywhere.
Then we came home

Exhausted lol. We were there four days (two were traveling days though). I think a week would have been best to really get to see all the side things I wanted to - Maritime Museum and Fulton House in Rockport, a beach day at Beach Access 3 (south Mustang Island) would have been great. We never got to check out Padre Island's beach. Didn't get to try that fudge or peek inside Popsicle Toes and tons of other neato looking shops in Port Aransas, Rockport, and Fulton

Would have wanted to do a Dolphin Sunset Cruise (various ones at the different little towns) but hubby gets seasick.