The local pool is a circus, I don't like being there at all. I'm thinking about something like this:

Any thoughts? I have a rowing machine but I don't think it's working those muscles. When I'm surfing regularly it's not as much of an issue (although I could always be a stronger paddler)
I'm looking for a home exercise when I cant be in the water, mostly in the winter. We can be blown out for long stretches.