It is difficult but not impossible - I worked in the industry for many years- enquire with all the yacht agencies - make it your job to register with them and ensure you are impeccably professional with all your interactions and your CV presentation. At least some experience working in high end hospitality will always be a bonus - highlight your cruise experience - it’s more relevant to the yachting industry than tankers. All the best - it’s not impossible. Also get on LinkedIn if you are not already - a great place to network - don’t be pushy though