If the National Environmental Research Council’s underwater robot can travel under the polar ice cap and send data back (Southern mission sounds like a job for Boaty McBoatface, 13 March), one suspects that the US and Russian governments possess even more sophisticated drones. Does this not further indicate the absolute uselessness of our “nuclear deterrent” submarines in the presence of such underwater robots? Would it not be better to spend the billions of pounds on something more useful, such as health, education or even on more appropriate conventional means of defence?

Dr David Prime

Trefriw, Conwy

• Join the debate – email guardian.letters@theguardian.com

• Read more Guardian letters – click here to visit gu.com/letters