Multicarrier modulation in the form of OFDM facilitates high-rate transmission over long dispersive channels, while multiple-input multiple-output (MIMO) techniques increase the system capacity. In this paper, we report on the design of a MIMO-OFDM with two transmitters and test it using experimental data recorded during the AUV Fest, Panama City, FL, June 2007. Nearly error-free performance is observed with low-density parity-check (LDPC) coding. With a 12 kHz bandwidth, the overall data rate is 12.18 kbps after rate 1/2 coding.