They are on guard dutty. Do you have the same question about human military guards? 99.9% of the time they are just standing around “doing nothing”. If the tr

They are on guard dutty. Do you have the same question about human military guards? 99.9% of the time they are just standing around “doing nothing”. If the trainers are any good they regularly excercise the dolphins with simulated “attacks”. > but who places mines there? Potential enemy saboteurs? Countries in the west has a long history of military infiltrators who are trained to swim/float to enemy ships and place limpet mines on them. These attacks are relatively low-tech, besides the limpet mines everything else can be bought from general sporting good / diving stores for it. Therefore we can assume such attacks are widely available to our enemies (large and small). Here is a few examples from history of such attacks: https://en.m.wikipedia.org/wiki/Operation_Jaywick https://en.m.wikipedia.org/wiki/Operation_Jaywick https://en.m.wikipedia.org/wiki/Operation_Frankton https://en.m.wikipedia.org/wiki/Operation_Frankton Obviously all these documented cases are from the second world war, and they used folding kayaks. You can assume that a modern infiltrator has access to improved gear to stay underwater longer, devices to help them swim faster and some will have access to rebreathers too so they won’t leave a bubble trail.