I have a technical background and am interested in this space. Feel free to reach out via chat for an initial conversation.

Satellite internet for boats, marine batteries & solar paneling spring to mind. Other tech in boats related to navigation and entertainment systems or safety. Talk to boat owners and crew about what their pain points are. Develop new sail technology, self driving boats, develop a system which maximises pontoon profitability at marinas. Airbnb-style business for boat owners. Target people who live on their boats? Took me 10 minutes to think of these and I don’t have much sailing experience.

If this is software (you don’t specify) make the product skinnable so that you can customise the design for each client in a config file. This is often called whitelabelling. Up-front production costs might be higher but you reap the rewards later. I did this for a large insurance firm who sold the system to multiple clients. We could build reskins of an e-commerce site in under a week.

Which one did you use? Just the name will do if links aren’t allowed