Mobile underwater networking is a developing technology for monitoring and exploring the Earth's oceans. For effective underwater exploration, multimedia communications such as sonar images and low resolution videos are becoming increasingly important. Unlike terrestrial RF communication, underwater networks rely on acoustic waves as a means of communication. Unfortunately, acoustic waves incur long propagation delays that typically lead to low throughput especially in protocols that require receiver feedback such as multimedia stream delivery. On the positive side, the long propagation delay permits multiple packets to be "pipelined" concurrently in the underwater channel, improving the overall throughput and enabling applications that require sustained bandwidth.