@Gary *********
buy ticket at Ekkamai bus station in advance or on the day. Big bus 180b. Smaller bus 200b. Big bus has a toilet. At Ban phe find ferry pier 50b ferry 30 mins or speedboat 15 mins
*****
one way 400b return (varies on where you buy it) Nuanthip pier seems the nicest and most organised pier. Although there are 2 or 3. If you know when you are coming back buy a return ticket for the bus and the speedboat and then you will be told where to go for the return boat/bus because otherwise you may end up in a different pier for your bus back. (From experience). You can buy bus ticket back to Bkk from Nuanthip pier to Ekkamai. Also some buses go to mo chit. So be careful.