How can digital reward systems be applied to traditional marketing strategies

So very new to ownership. Have had boats my whole life but this is the first non outboard. Bought the boat a few weeks ago. Ran great when tested. Took to mechanic to winterize and when he checked it oil it was very milky. He says engine is most likely shot. What are the things I should be double checking...

Known issue with the transducer (triducer) are there any compatible alternatives to the original 800 model that constantly fails. I'm trying to change this out without any additional programming or modules.