Travelling to the Samui Yacht Club is easy and comfortable; either with the plane or going overland with train and ferry.
... via plane ... your travelling over Thailand's capital Bangkok. All international airlines offer regular flights going to 'Don Muang Airport' (abt. 25 km to Bangkok's center). Here you take another flight operated by 'Bangkok Airways' and within abt. 60 minutes, you'll be on Koh Samui. (Your travel agency may reserve seats and / or order tickets for this local flight.)
... overland ... you're taking the train from Bangkok to the city of Surrathani (please reserve the nighttrain 3-4 Tage before travelling). In Surrathani you'll be taken to the ferry-pier by bus. There are many ferries daily (speedboat or carferry) connecting Surrathani with the island of Samui. Arriving either in the old port of Nathon or the newer ferryport, you'll just take a local taxi and ask for Samui Yacht Club.