Intellectual Property Refusal reason

In addition to the comments from others here, the monochrome conversion would also earn a rejection since black and white images are not accepted.

Are there identifiers on the boats?

Anyhow, I would also assume that this asset would be refused for quality issues. 

And yes, there are common mistakes to avoid. You can study this forum for seeing examples. And you should have a look into the manuals: If you are new to stock, you should consider these resources: https://helpx.adobe.com/stock/contributor/tutorials.html
Please read the contributor user manual for more information on Adobe stock contributions: https://helpx.adobe.com/stock/contributor/user-guide.html
See here for rejection reasons: https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
and especially quality and technical issues: https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html

The photo is too small for us to judge. Please upload the original. 

If there are any identifying markings on the boats, that is a reason.

But, I assume, and this happens alot, the reviewer checked the wrong reason. I assume it was rejected for quality. First of all, monochrome is not wanted. Also, the sky appears to be without details.

Hmm my take on it is:
Was it generated with AI? If so, it might resemble or be a copy of a real photo that is already on the marketplace.