Magnetic resonance wireless power transfer can provide continuous energy for the underwater equipment. Moreover, the energy waves carrying information can also construct a high speed and reliable channel for data communications. Therefore, both the power supply and data transfer bottlenecks are broken. In this paper, an underwater simultaneous wireless information and power transfer (USWIPT) technique is investigated. A prototype based on field programmable gate array (FPGA) was developed, and the frequency-shift keying (FSK) modulation was employed to achieve wireless information and power transfer. While the input power is 20 W, the data rate is about 1 Mbps with low power consumption in the underwater environment. To avoid the channel changes due to the mobility of underwater devices, a support vector machine (SVM) based method was proposed for the signal decoding. Experimental results showed that, the proposed system can work under the high speed transmission and long distance, and the decoding accuracy can reach 99.9%.