After our Friday evening cruise, our Yamaha T50 started with an audible alarm when in neutral. With the help of Google, figured out the engine fuel/water separator was full. I emptied it out and replaced the external filter and no more alarm. But, I find it interesting that there was that much water that made it to the engine filter considering there was an external filter. Granted, I haven't replaced the external filter annually. When I took the external filter off, I dumped it into a clear container and let it settle. There wasn't any obvious signs of water in the container. When I emptied the engine separator bowl, the water was easy to see. I've always used non-oxy fuels and treated them with Sta-Bil Marine as insurance. With the daily temperature fluctuations and humidity levels of the northern summers, I wouldn't be surprised if the tank had some water in it due to condensation. I guess from now on, I'll be trying to keep more fuel in the tank all the time and stick to annual changes of the external separator.