Running issues

So Memorial Day weekend we made it out to the lake.....only the fun lasted about 30 minutes before I lost power to the boat and had to be towed back in. Figured it out and repacked the ignition coil as we were getting no spark. Was able to start right up. Now a couple weeks later was able to get it out on the lake again...and the exact same thing happened. Haven’t been able to check yet but it seems it’s the same issue again. Only we had only been on the lake for maybe 10 minutes....boat loses power and is acting up under very little load. Killed the boat and it would never start up again. Will be able to get home after work today and start checking on things but it’s the exact same issue. Is there a reason the ignition coil would go out again or would something be causing that?