Here is how to train for a long swim:
Dream for as long as is necessary. Then settle on a goal. Goals don’t happen without dreams, and nothing happens without goals.
Now stop dreaming and focus. Focus on your goal the way you focus on your breathing, your stroke technique, or your counting of laps during a long pool set.
This swim is going to be hard. (You knew that, right?) Make your training harder. Train longer. Train faster. Train colder. Train farther. Train before dawn. Train through sunset, through dusk, and into the dark. Just you and the inky abyss.
Study everything. Study past successes and failures, both others’ and your own. Study the tides. Study the course. Study the coasts and the towns along them. Learn physics, biomechanics, nutrition, chemistry. Learn to stay organized. Read everything you can. Never read motivational posters; they are the worst. Don’t blindly trust the experts, check their assumptions. Become the expert, check your own assumptions.
Make mistakes and learn from them. Ignore the tides and get stuck in a current. Drink too much the night before. Skip breakfast. Lose goggles. Forget your suit. Now make those same mistakes again. Understand what part everything plays, and know what to do when mistakes inevitably happen.
Now make your training even harder. Make it too hard. Too long. Too fast. Too cold. Too far. You don’t know what any of those things are! Stop whining, shut up, and swim.
Make friends. Make contacts. Make whatever you need to succeed if it does not already exist. Lose friends. Lose contact with the outside world. Lose touch with reality as everyone else knows it. Make your own reality.
Swim all the time. Swim through Love. Swim through Loss. Swim through all the emotions that come in between. Never ask if swimming is the cause or the cure. It is probably both, but knowing that won’t help anything. Swim as your life crumbles around you. Swim while you rebuild it. Never stop swimming.
You knew this was going to be hard, right? Accept it. This will be lonely and alienating. Your only friends will be swimmers, and even they won’t understand you. This is a path that few have taken, or ever will. Don’t expect many companions. Treasure those who join you.
Happy endings are never guaranteed. Accept that things are not always in your control. Train yourself to appreciate small victories. Everything brings a chance to improve, to learn, to succeed. At best, your training will be adequate and your swim will seem easy. Don’t dwell on the other possibilities.
If this doesn’t work: make your training harder. This will not be easy. But you knew that, didn’t you.