We decided the day before as we were driving through Kapaa to rent bikes the next morning. I had read some reviews before our trip, but did not make reservations since we were just going day-by-day. What a great decision! We got there first thing in the morning, rented our bikes with no problem (the guy at the front was super friendly), got situated on our cruisers and headed off! I believe the path was 4 miles down one way and 1 mile the other (so if you go the whole route 10 miles). The 4 mile stretch is beautiful, what a great way to see the coastline. The path was not that busy so it was very enjoyable. There are several picnic tables and places to stop and enjoy the views. I highly recommend taking a few hours to do this.