hey pmac
First — thanks for giving a part of your life in service to your country.
The ROV business employs most people in the offshore oil and gas business. It’s cyclical. Now is a down cycle. Two years ago if you could spell "ROV" you could get a start. These days there are plenty of trainees and newcomers. Bad time to get a foot in the door. ANY training you get and experience with hands on electrics/electronics, hydraulics, mechanics will be beneficial. A degree is not as important as a proven record of successful performance in any or all of above.
Try Oceaneering in US. With your service background they’ll at least talk to you, point you in right direction to get what they are looking for. OI actively recruits ex military. For a guy starting they have the best overall training and startup program of US companies. I don’t know if Ken Cash is still there in the Louisiana office but he’s a good one to call for and ask for direction.
Your GI Bill benefits entitle you to a myriad of educational options. Look for somehting that is hands on vocational rather than a four year degree program. At this time I would not recommend a commercial ROV training course as your first option.
Good luck and drop a line here down the road with progress.