To get some salt water time, gently, in Texas you can go out of Corpus Christi onto South Padre Island and dive the lee side of the island. You drive to S Padre Isl and just after you pass the pay to get in place there is a turn off to the right to Bird Island Basin. You can snorkel and scuba there. The water is shallow, but the vis can be 10 feet...if the wind speed is low. There are Moon Jelly Fish to see, they are the size of dinner plates and have tenticles only 2 inches long or so. If you touch then gently on the top surface and don't poke them they won't dump sting sacks into the water and make 'stinging water' around themselves. There are other marine fish to see there too.
If you want to go on a rig trip contact Captian Mike Miglini. Capt Mike M owns a boat called the Orion and he runs really good trips. The difference between his trips and others I have been on is that he takes a second Captian, Capt. Mike Wofford along to run the boat and help with the entry and exit. Capt. Miglini will often be in the water to aid divers if they need it. Dive master and first mate Skip Dominguez will probably be along to watchover divers too.
The Orion crew tieup the boat to the rig like everyone does but they also run a downline from the stern to the rig at a depth of about 40 feet. This downline allows divers to get from the stern of the Orion to the rig by pulling themselves thus saving air. It also is a path for divers to go from the rig to the boat. The Orion has a set of inflatable signal sausages for the divers to use to make it easier to find anybody who gets carried away by the current. I used to laugh at divers who got 'blown away' until it happened to me. On the other hand some divers who get swept away have excellent dolphin encounters, or in my case Crevale Jack company. (It was my fault, I fooled with my camera and spear gun when I should have been swimming to the rig.)
The trips are three tanks, usually two tanks at one rig with an hour surface interval and the third tank at a different rig. I like to spend the surface interval snorkling.
These are primarily spearfishing trips. I have done spearfishing and or picture taking on these trips as well as just looking and playing around. All these things are fun. Depth can be from surface to about 70 feet. The good fish are from 20 to 40 feet usually. Vis can be from excellent to only 20 or 30 feet. Vis can be bad down to 40 feet and good below or good down to 40 or 50 and bad below. In the fall the water is warm down to at least 135 feet. Sometimes I don't use a wet suit, sometimes a 2/3mm $49.99 wetsuit from Academy Sports and Outdoors in San Antonio or Corpus Christi, sometimes just a long sleeve shirt and dockers pants. Bare skin can take stings from stinging coral.
Fish just love oil rigs. There are always lots of fish around. Barracuda will be on patrol. You can eat oil rig barracuda and they are fun to shoot..or to just watch. You will see sheepshead, spade fish (angel fish) and lots more. Sometimes there are little orange 'nemo' fish and always yellow and blue fish. Sharks are always there but I never see them when I'm spearfishing, but do see them if I'm doing photography. $10 disposible underwater Kodak cameras from Walmart or HEB grocery stores take good underwater pics, take one for each dive.
The oil rig is made of steel tubing ranging from a size you can straddle and hold onto like riding a horse to massive. The tubing will be covered with marine growth. You can hold on to the barnacles on the tubes and just chill out and watch the world aquatic, jump from tube to tube, use a magnifying glass to see the small things, use your dive light to see the colors and all that. Current can be strong or weak and can vary a lot in speed with depth. Surge up and down can be absent or extremely strong, but is usually less at 40 feet than at 20 feet. The only guy I met who didn't like a rig trip was a fish hugger who freaked out when guys shot "sacred fish" and ate some raw on deck. It is just about impossible to not have a fantastic time on an Orion rig trip. (take dramimine the night before, that morning and again on the boat.) The Orion leaves from Fisherman's Warf in Port Aransas about 8:00am, get there early, bring sodas, water, eats, suntan lotion, a hat, sunglasses, your dive gear including tanks, weights and stuff.....and get ready to rock n roll in the H2O!
Usually the Orion will hang a tank at a good decompression depth in case it is needed and also hang a line to attach spearguns to so that they don't have to be carried onboard during boarding. Capt Wofford or somebody else is always there to catch fins tossed up, fish tossed up, spearguns handed up and to help the divers board.
Look up Captian Mike Miglini, or the charter boat Orion on the internet and give him a call. Talk to him about what you want to do. He and his crew sure run a most excellent trip.
Let us know where you go and tell us the story.