Due to the weak wireless connection and limited coverage of maritime communication, this article uses unmanned ships as communication carriers to improve the wireless connection capability and coverage of maritime communication. In response to the problems of short communication distance and high error rate between base stations and unmanned ships, hybrid beamforming technology is introduced. Hybrid beamforming, due to its ability to improve signal transmission range and signal anti-interference capability, can solve the safety hazards of busy water navigation. This article selects bit error rate as a performance indicator to measure transmission reliability, with the minimum mean square error criterion as the optimization criterion. In order to solve the problem of multivariate optimization, this paper introduces the alternating iteration method to optimize the digital and analog precoders. In response to the constant modulus constraint problem in analog precoders, this paper adopts a Manifold optimization algorithm to transform the constant modulus constraint into a gradient optimization problem on Riemannian Manifolds. And conduct simulation verification based on the number of antennas for users. The simulation verification results show that under different antenna numbers, hybrid beamforming has good performance in spectrum rate and bit error rate, and has good anti-interference ability, which can provide technical support for navigation safety in busy waters.