The first two would get to the junk pile before Shiro does since they don't have a problem with the currents, but that's before Ebon remembered he didn't know what he was looking for. By the time the second two arrive Shiro would be in the middle of texting. Unfortunately his R-Types don't have darkvision, so they have to use a searchlight. Shiro should be able to see them, if not because of his night vision, then because they have a bright light to scan the bottom of the lake.