By "the gulf" I'm assuming you mean offshore? There are others here who have a lot more experience kayak fishing offshore than me like Christian Myrick. But here's what I've learned and what I carry offshore.
Practice going through the surf unloaded. Then practice loaded with all your gear. Google surf landing backwards and try coming in backwards first. It's easier and you don't turtle nearly as much. NEVER go offshore alone unless you're experienced. Always let someone know that's not going to be with you where & when you're launching, who your with and when you think you'll return. Check as many tide & weather forecast sites as you can. The tide forecast is what lots of folks focus on but forget to check the weather. Windfinder is good for both wind and tide forecasts, Magic Seaweed has surf forecast and so does Windy.com. I use NWS & Wunderground for weather forecasts. Leash everything. Seriously if you want to return with it leash it to your kayak.
What I carry:
Leader bag- this is basically a worm bag that I put all of my steel leaders in, leashed with paracord
Worm bag- this is the same thing as my leader bag (but a different brand). I put my jigs, lures and any snapper rigs I have made up in this bag, leashed with paracord
2 offshore rods/reels and 1 inshore spinning reel for catching bait, all leashed with paracord
FIsh grips (or Boga), fish gaff & or spear, knock out bat to hit fish in the head with, all leashed with paracord. There are lots of DYI's on fish gaff's and spears. I found I can buy a decent gaff for about $20 which is what it would cost me to buy the stuff for a DYI. Here's a good video on a DYI fish spear- https://www.youtube.com/watch?v=t6s...frNgrw5MKBKWwpeC4f8&index=3&t=0s
Wire or side cutters (in case I get a hook in me and need to cut the shank off)
Pliers for getting hooks from the fish, leashed
I carry a pair of kitchen shears to help cut up bait, leashed (a knife will also do)
Something to measure fish with (I use a cloth sewing measuring tape cuz it doesn't take up much room- $3 at Walmart)
Of course a PDF worn at all times- on the PDF I keep my marine VHF radio, my phone (inside one of the pockets) and a knife
Gloves to be worn
Dry bag- this has lots of stuff I may need for all types of fishing- basic first aid kit, TP, extra shirt, paracord, hand towel, rain poncho, lighter and headlamp.
Drink/snack cooler- this is huge especially this time of year. I will freeze a couple water bottles and a Gatorade bottle for later in the trick so it'll still be cold. Less ice/weight I need for my drink cooler.
Fish bag- if you intend on catching fish. There's a post on a good economical fish bag for offshore fish here- https://texasfishingforum.com/forum...rts-fish-bag-great-fish-bag#Post13206061
Again keep it light as possible but make sure you have what you'll need.