You can use Taxi or Boat. Boat will be fastest way to reach the meeting point if you stay around the Sukhumvit area. Take the boat to terminus Phanfa Leelard station and walk 2 mins. Check this website for further information : https://www.transitbangkok.com/khlong_boats.html
This activity ends back at the meeting point.
6 hours to 7 hours
2 hours to 2 hours 30 minutes
3 hours 30 minutes
3 hours to 5 hours
2 hours to 3 hours
1 hour 30 minutes