Providers are only selected when the output is a product or waste flow. In your case it sounds like "antifouling paint emissions" should be treated as an environmental flow - a direct release to the environment with no further modifications.
If this is a brand new flow you are creating, you can then add it to your LCIA method with whatever characterization factor is appropriate, or use the characterization factor from another database such as what you are using in SimaPro.
