The Klonghae Floating Market is actually situated by a river and is divided into three sections. A general area where stalls are stationed on land with seating areas, the main boat hawkers which are stationed by the river and across the bridge on the ground. While the tourists will flock to the riverside for the amazing experience, the locals mostly hang out at the main area. I believe you can easily spend a good 30-45 minutes by the river before moving to the seated area.