When ships navigate in restricted waters, the water flow structure is very complex due to shallow water depth and narrow water surface.The turbulent characteristics around the hull in restricted waters are studied on the basis of particle image velocimetry(PIV)flume experiment, and the distribution characteristics of longitudinal turbulence intensity Tux, Reynolds stress τ, turbulence kinetic energy k, and their variation with cross-section coefficient are explored.The results show that the longitudinal turbulence intensity Tux and turbulence kinetic energy k of the mid-section of the bow are both affected by the hull walls, with the maximum values concentrated at the bottom of the water flume and near the bottom of the ship.The maximum Reynolds stress τ occurs near the bottom of the flume, and is negative at the bow surface and near the bottom of the ship.Tux and k in the front area of the ship decrease from the bottom of the water flume towards the water surface, and τ first increases and then decreases vertically.The stern reflux zone forms a long elliptical shape with high values of Tux and k, as well as negative values of τ, and diffuses downstream.As the cross-section coefficient increases, the high and negative ranges of Tux, τ, and k decrease, and the inflection point of k shifts upward.Increasing the cross-section coefficient can significantly reduce the squeezing effect of the hull on the flow, reduce the influence of the hull shape on the flow, weaken the turbulent momentum transfer and exchange, reduce local high-intensity turbulence, and increase the stability of the flow field.