Will be funny
to see how your application can be covered by the S63 license
S63 states explicitly that the cells are licensed for one system and a given underlying product (software in the case of OpenCPN).
You can't use cells licensed for OpenCPN for other plotters. And vice versa. This is enforced by encrypting the chart material with a key that is linked to a given product.
What would be possible (let's say for a boat's bridge system) is to replicate the screen
But what the license
terms would exclude is to use the data independent from the system they have been licensed for. Unbundling them.
So what you would need is A) a system that is entitled to license S63 chart material and B) that is rendering those charts. OCPN would do both in your Linux environment
When you export these renderings i.e. in a different format in order to apply them in other processes independent from the system they are derived from
, you are on a slippery road, I fear.
You might discuss this with the IHO as the holder and guardian of the S63 scheme.