As a full time yacht cruiser, it would be very convenient to see a lat/ lon overlay. Is this possible?

I like Windy. It is one of my two main sources for marine weather. When they offered Pro at a discount I bought it. It's still new to me so I'm not ready to review it. However I am concerned that the sea state forecast (height of swell and period and wind waves) is very different. The data for swells is even the same. Which one is correct? If Windy basic is correct then Windy Pro has a problem. If it's the other way then Windy basic shouldn't include the data in the display. What is the explanation?