If you are staying in Poipu or Kalaheo and are looking for a good paddle, consider the Hanapepe River. It’s less than a mile from where you put in to where you can’t go further upstream but it’s fun and interesting and pretty easy!
The best put in spot is just upstream from the old car bridge. There is a building on next to the bridge and just beyond a short dirt road goes down below the levy. Park there and you’ll find a path to the river near the bridge.
You can go downstream into the bay if the wind is light, but I wouldn’t suggest it otherwise. We were very close to being pushed out into the middle of the bay the day we tried it.
Going upstream is much better. The river is surprisingly shallow but plenty deep for a kayak or paddle board. You’ll travel between levies and go under the famous walking bridge. Upstream further you pass by a very high cliff on your right. You turn a corner and the whole environment changes. You can see large schools of fish passing right under you. There are trees with branches that touch the water. It’s quite spectacular!
Keep going around another corner and you’ll come to a short waterfall where the water really gets shallow. You’ll often see folks fishing or just taking it easy along the banks.