RYA SRC 1 day course

Yes, you have to pass the DSC element of the course.
You do not have to attend the rest of the course if you already have the VHF certificate, but I don't think anyone offers a discount just for the DSC bit.
It may be a good memeory jogger anyway, and they usually serves coffee and biscuits.

Last time i looked it was around £85 for the day including the Exam costs.
 
There are essentially 3 option

Most people go for the 1 day Short range certificate (SRC), costs Cira £80 plus £30 license fee

OR

If you hold the old VHF certificate you can take a 3 hr Dsc upgrade course, costs circa £50 plus £30 license fee.

OR

If you don't fancy the course you can simply attend an exam, can't remember the exam fee but it's about £65
 
Top