So what is your fix sir? Do you offer a solution?
You're not going to like my answer. The solution is to find a way to pay your insurance. If you don't have the money to pay your premium, you are certainly not going to have the money to pay the damage you do to others' boats and docks if your boat catches fire. So in my opinion you are a bad neighbor. If you cause damage to others, you are likely to disappear rather than face up to your financial obligations.
...Or do I just have to sit at the dock?
Actually, sitting at the dock is probably the most irresponsible thing that you can do, because it is the place where you are most likely to damage others' property. Without insurance you should cast off from the dock and not come back. I'm surprised the marina allows you to stay there without insurance.
...Either I have insurance for a boat that I cannot afford to cruise
Or I don't have insurance for a boat that I can afford to cruise...
It could be argued that you cannot afford to have your current boat. It's nobody's fault but your own - you should have included the cost of insurance in your calculations of total cost of ownership. If you can't afford the insurance, you should have chosen a more affordable boat.
...Far from a dead beat sir, I just cannot afford it.
Isn't that what all deadbeats say?
Or someone stops charging out the yang for 30+ yr old boats worth less than 10 k seeking only liability.
The cost of your boat has little to do with the likelihood of damaging other boats. As a boat ages and its value depreciates to nothing, it is more likely to have electrical problems, fuel leaks, and other issues that make it a greater risk to catch fire and/or cause environmental damage. That's why the premiums on old boats are often so high. Your argument about lack of financial resources reinforces this, because it suggests that your maintenance may be inadequate.
Don't forget: Insurance companies want your business. They compete with each other to get it. They will offer you the lowest rate that their actuaries say will allow them to make a profit. If you're getting high rates from everyone, it is because there is a risk factor which tells them that they are unlikely to make a profit on you. There's nothing sinister about that - it's just business.
Look, I know what I'm saying isn't what you want to hear, and I suspect you'll come up with all sorts of reasons why I am mean-spirited, closed-minded, or just plain wrong. So just stay away from my boat (and the boats of other responsible boaters here) and we'll call it even.