Well...shucks. I've had a broken back and also have problems with the connection between the sacroliac and the hip. It can, and does, go out at any time. Inactivity makes it worse. Weak muscles make it worse. One big problem was an imbalance of core strength that was result of a lifetime of work. I had, and still have, to do balanced exercise to keep my core strength strong and in balance...otherwise more injury occurs. It is natural to avoid anything that might hurt you....but it seems, in my case, that it was best to exercise until the muscles were strong enough to add the support needed. As I get older I also have a lot of trouble with arthritis...but that doesn't stop me either. One key to my exercise is to do balanced exercises based on the weaker side...and increase the exercise as the weak side strengthens. I also don't use weights, or exercises, that will cause a lot of pain. I keep just under the very uncomfortable pain threshhold. The result is that in the last 4 years I've increased my strength, joint strength and mobility, and decreased my back problems. These are just my experiences. You'll need to decide what you're gonna do for yourself.
I also think Verlin Krugers boats are something to look at. Great, very stable, and efficient boats. You can do just about anything you want with them.
Have fun. Good luck.