I am new to the forum. I do have some knowledge on this matter as I am an insurance adjuster dealing with marine claims. First off, I am not sure what you are referring to about an"umbrella policy". You can with some insurers cover your home and boats etc., under 1 policy but the boats usually fall under a maximum size and horsepower limit. Anyone who carries less than 2 million for liability coverage or no liability coverage, is playing a big game of Russian Roulette. You have yourself and 2 friends on the boat. You are motoring along in the fog and collide with another boat. Your 2 friends and 2 other people in the other boat are either killed and or seriously hurt. You say you did everything right. Had my running lights on, had a look out, had the radar on. All the courts will have to ask you is one question: Should you have gone out in the fog? You had a better choice to make. You could not have gone out. Liability found on you as the captain of that boat, and also on the captain of the other boat. I had a claim like this. Judgement was 3.5 million. Your boat sinks at the dock, bilge pump failed. Oil and fuel discharged into the bay and affected a fish bearing stream. This is "Absolute Liability" no excuses. Judgement 1.4 million. You take your buddies out for a fun day on the water. You let one of your buddies operate the boat without a boating certificate. He gets up on plain and collides with a kayak. Judgement 2.3 million. These are actual claims. $415 or even $1,100 now sounds like a bargain compared to losing your boat, home, vehicle and paying for the rest of your life.