With the development of the smart ocean which contains a large number of wireless sensor nodes, it is a great demand to develop high-performance marine energy harvesters for powering those sensors. In this work, a highly adaptive hybrid nanogenerator based on triboelectric nanogenerator and electromagnetic generator is proposed. The hybrid nanogenerator can be used for scavenging both wind energy and ocean current energy. The peak power of the hybrid nanogenerator can reach 449.74 mW, which can recharge a 50 mAh-3.7 V Lithium battery. In addition, it is found that there is a linear relationship between the voltage frequency of the triboelectric nanogenerator and the rotation speed, indicating the hybrid nanogenerator can serve as a flow velocity sensor. A fully self-powered marine wireless sensor node is fabricated based on the hybrid nanogenerator and management circuit. The demonstrations show that the present hybrid nanogenerator has great potential applications for marine wireless sensing in the scenarios of nearshore, offshore, and underwater.