There is a lot that can be said about training for a marathon swim that doesn’t need to be repeated here. In a way, a marathon in the Pacific Northwest is the same as a marathon swim anywhere. In a way, its very different.
Rather than plagiarize a bunch of stuff here, just go to the source.
The Santa Barbara Channel Swimming Association has a great preview of how to train for some major ocean swims.
You’ve mastered the easy stuff: you can swim for hours, you’ve figured out your nutrition, and you don’t chafe the way you once did. You’re ready for something harder.
First, you’ll notice it is colder in the Puget Sound then a lot of places. Even in the summer, the water will rarely break 60F. And in the Strait? You’ll be luck to see something above 50F.
There are no two ways about it, you need to be ready for the cold. It is doable, it really is, just don’t let it catch you off guard.
Take a look at the Cold Water FAQ page for some specific information on a different type of Seattle Freeze, or for a less local perspective, read through some of LoneSwimmer‘s extensive writing on the topic of cold water swimming.
The weather in the Sound isn’t too hard to predict. The wind will be coming from one of two directions, and it will with be sunny or almost raining. Sure, the Northwest has its calm days, but when the wind blows, it blows up or down one of the water bodies, pushing up waves with ease. Add those waves to a current in the opposite direction and you’ve got white caps.
Be prepared to swim into the wind and waves. And we aren’t talking big Pacific swells, just the little, annoying waves that break right where you are trying to breathe. Any north or south facing beach will give you the opportunity to practice this.
This is where your speed work will come in handy. With any luck, your pilot will guide you around all of the eddies and whirlpools in your way, but you’ll be better off knowing where to expect them. A flat calm day can turn wild in a moment where two currents meet, and being comfortable in rough water will pay off big if you can keep your head down and swim when that happens. Likewise, your swim may require a hard swim into the finish if near-shore currents start to pick up. Pick up some charts or pick up the phone, but get the currents right.
A lot of discussion occurs at the Marathon Swimmer’s Forum. Use the search feature, and don’t be afraid to ask.