Went to San Diego and attended the 2010 underwater autonomous competition. This is an event that has been going for the last 13 years and attracts college students from around the world. This year there were Japanese, Korean, Canadian, Icelandic, and US teams.
Although the competition is open to college students, these folks are more engineers than students. They devote countless hours doing these projects and many of the robots there are very professionally made. There is a lot of debate on the fact that a lot of students in the USA are not embracing careers in science and engineerings. These young people do not have that issue.
The great majority of the teams competiting were using Intel (only one was not). All the top teams were using high end procesors such as core 2 duo. This year winner, Cornell University (see picture of robot) was using a quad core processor.
The main challenge in creating underwater robots, besides the fact that they go under water, causing for the most part countless mechanical issues, is the navigation. UAVSI, the organization that puts together this event, focuses on unmanned vehicles.
Most of the students are very proficient in vision processing algorithms, tools, etc. The majority are using a version of linux.
follow me on twitter @intel_marcos