Mary,
The decline in strength and endurance that you and Rick experienced in your mid-40s is par for individuals who haven't been on a regular training program. Some individuals experience that decline before "the 40s", some a little later. It all depends on what you are asking your body to do. If you don't do a whole lot, it takes a "jolt" to realize that you can't do a whole lot.
Active people sometimes come to the conclusion that their "participation" in a particular physical activity is no longer enough. In comes "resistance training" and "cardiovascular training". Question is: "how much do you need"? Well, you need a level that enables you to comfortably accomplish your everyday tasks, enjoy the physical activities of your choice and have a "reserve" for the unexpected over and above your specific needs. This is going to be different for everyone. The catsailor that is "content" with putting the wife, kids, dog, and beer on board for a little Sunday afternoon cruise does not require the strength and stamina of aggressive cat sailing teams. Although, it certainly would not hurt him.
There are many exercises that would benefit the catsailor. And, there is a variety of equipment that can be utilized. I would need a "whole lot of time" to elaborate on everything. You would be on the right track if you were to train "all" your muscles. Legs, upper back, lower back, chest, shoulders, neck, abdominals, and arms. I would make sure to include flexibility exercises. In conjuction with the resistance training, or as a stand alone such as Yoga or Pilates. If you really want to get specific, training for skipper and crew are actually different. They require different demands of their body.
The key to understanding training is that the stresses (and training is a stress) we place on our body is extremely "specific". The closer you can train to what your physical activity is...the better. You don't train a marathon runner by having him/her drag a stove down the road. By the same token, you don't train someone that will be sawing the mainsheet for extended periods of time by using very heavy weights, with few reps. For those with a good fitness foundation, there is also plyometric and ballistic training that can be included. What better way to be able to handle "severe" "unexpected" stresses on the body, than to train the body to accept them. If I had to choose one exercise that utilizes a majority of the muscles used in catsailing, I would give high marks to a rowing machine. There are crossovers between extending the legs from the "compact position", "contraction of the lower back muscles while bringing the upper body back from a bent over position", "upper arm muscles contracting while drawing the fists toward the chest", "shoulder girdle muscles contracting while drawing the elbow back", "abdominals contracting in the layed out position". If you think about it, there is a fairly close relationship there.
O.K., I've probably rambled enough on a subject that I dearly love. As you can see, like sailing, the more you know-the more you realize there is so much to know. You may find this site of interest http://www.exrx.net/Exercise.html
Thanks for listening.
Dave