Ok, since you wouldn't (couldn't) take my "shake it suggestion" perhaps you should try a more vigorous on-shore training regimen.
Either at home or your favorite watering hole (with designated driver) drink three beers as quickly as you can. Now, think of a reason why you absolutely have to stay where you are (big play in football game, interesting conversation with 'person of interest', notice long line at the bathroom door) these will generally cause a spontaneous and overwhelming need to pee. Allow yourself to 'release' at your earliest convenience, but but continue to drink beer at a moderate pace. You'll pee often. This will train your muscles 'there' to communicate with your brain. Repeat this training session as often as your head will allow. View attachment 104540
Either at home or your favorite watering hole (with designated driver) drink three beers as quickly as you can. Now, think of a reason why you absolutely have to stay where you are (big play in football game, interesting conversation with 'person of interest', notice long line at the bathroom door) these will generally cause a spontaneous and overwhelming need to pee. Allow yourself to 'release' at your earliest convenience, but but continue to drink beer at a moderate pace. You'll pee often. This will train your muscles 'there' to communicate with your brain. Repeat this training session as often as your head will allow. View attachment 104540