IArt.
What doesn't work
Your core value proposition is contradictory. You claim to be a seamless, API-first platform, but your go-to-market is based on a high-friction model of uploading dirty spreadsheets. This isn't a bridge; it's two different businesses. One scales, the other is a service company in disguise.
IIArt.
Biggest risk
The biggest risk is behavioral. You assume shipowners, under regulatory pressure, will do the hard work of fixing their internal data processes to use your software. It's more likely they'll stick with the familiar consultant who promises to 'handle it,' even if it's less efficient. You're betting against inertia, which is almost always a losing bet.
IIIArt.
Key question
What happens when your first major client, with a fleet of 200 ships, says your system is too rigid and demands you build custom tools to clean their specific 'dirty data' or they walk? Your answer to that question defines whether you are a product company or a consulting firm.