On its own the one day RYA course will cost around £110 (approx. $165 or 155 EUROS) or though to get the full International Sailing Federation (ISAF) qualification it should be done in conjunction with the Sea Survival course for £220 (approx. $330 or 310 EUROS).
This course teaches advanced safety techniques in case you get into difficulty offshore and therefore with emergency services unable to react immediately. You will cover how to fight fires, where and when to use flares, as well as how to use a storm jib to stabilise the vessel in adverse conditions.
It is a requirement for all sailors to do this who are planning on competing in an ISAF offshore regatta or race in combination with the RYA Sea Survival course, though those planning an extended cruise can do this qualification independently. If you are to apply for the ISAF accreditation you should also get your First Aid certificate as well (see elsewhere on this website).
In theory this qualification will enable you to sail in weather too foul to walk your dog in. It teaches you what to do in extreme conditions in your yacht or boat.
This is entirely shorebased, though you should get a chance to fire a flare, practice man overboard, and use a fire extinguisher for a fuller experience of what it is like to use these in anger.
You can do the Offshore Safety course anywhere with RYA accreditation to teach it, which is almost anywhere in the world.
You should only do this course if you are a serious sailor, though there are no prerequisites to doing it.
It takes one day, however if you are doing the full ISAF accreditation you should do it with the one day Sea Survival course as well – as a combination it will take two days.
This course is an adjunct to your career progression as a sailor. You do this as part of your progression as a professional sailor or as a serious cruiser.
If you are going for the ISAF accreditation, it qualifies you to race anywhere in the world on an ISAF regatta or yacht race. With only the RYA course, you do not qualify except as part of your progression to the Yachtmaster certificates of competence.