The founder of our team had that kind of setup. A simulator of sorts for winter lol.
The basic idea was a platform right beside a tub filled with water in his warehouse/garage.
Dont know if you can spare a tub but there's always other ways to jerry-rig one.
Ex: buy a medium height (high enough for paddle length) kid pool (read: pvc) at cad tire/walmart, then build a wood plank across it as a seat? just a thought.
However you do it, its going to be expensive. I suggest cross training like kayaking, elliptical machines, swimming, etc anything to keep ur stamina up and upper body working.
Good luck!
