If all else is equal (ie licences and experience), the NS operators would rather them younger. (This is not necessarily the same viewpoint as the onshore market though.)
This is not to however to say that a more 'senior' applicant won't get accepted (needs must, and all that...).
NS crews will always have an experienced Commander in the RHS (even if he/she doesn't appear to be that old.) You can be a very experienced Captain at 25 if you started as an FO at 18.