During the winter and spring, the entire bay is subject to high surf, but when the sea is calm good protection is afforded from the trades. Midbay anchorage is in depths of 6 fathoms, sandy bottom.
A launching ramp is on the S side of the Hanalei River, 0.1 mile above the mouth.
Hanalei Bay has an entrance width of a mile between Makahoa Point on the W and the extensive Puu Poa Point reef on the NE; inland extent is nearly a mile. Breaking coral reefs fringe the shores on both sides of the entrance. Seas break across the entire entrance during N or NW gales.
Along the sandy beach at the head of Hanalei Bay are clumps of ironwood and coconut trees and the houses of Hanalei. The highway is close to the shore. Three miles inland the mountains attain heights of more than 4,000 feet.
The Hanalei River which empties into the E side of the bay, is navigable for shallow-draft boats for a distance of 2 or 3 miles. A privately dredged channel passes close to the reef on the NE side of the bay and leads to the river mouth. At high water, a depth of 4½ feet can be carried over the bar at the mouth and about 4 feet to the bridge 1.8 miles above the mouth. Overhead power and telephone cables with a clearance of 27 feet cross Hanalei River at its mouth.
A 300-foot long concrete pier, used as a shore recreation site for swimming and fishing, is on the E side of the bay and 200 yards S of the Hanalei River.