Should the Navy allow women to serve on submarines? The Defense Advisory Committee on Women in the Services (DACOWITS) — which also believes women should be able to serve in ground combat units if they want to — last week recommended once again that the Navy change its policy and put women on subs.

As Chairman of the Commission on Military Training and Gender-Related Issues, I have toured submarines and talked extensively with their officers and crew, as well as experts in medicine and physiology. What I have learned persuades me that assigning women to submarines would be a huge waste of money and would dangerously impair mission-effectiveness.

The living conditions on a submarine are difficult enough for an all-male crew. Sailors literally sleep on top of torpedoes, and many must “hot-bunk” — that is, occupy a bunk that is used by another sailor or sailors at other hours of the day.

On a submarine, every inch of space counts. It is normal practice to store cans and boxes of food in the shower stalls. Sailors simply go without showers for long periods on submarines.

Submarine deployments often last months. Depending on the secrecy of the mission, it may be impossible to return a sailor who falls ill. Submariners are exposed to dangerous fumes and radiation; these would be extremely hazardous to a pregnant crew member and her unborn child.

We already know from surface ship experience that women are evacuated at far higher rates than men, especially for pregnancy and similar female health issues. Not only does the loss of a crew member hurt the efficiency of the mission, but it also jeopardizes the safety of others, including the air crews who perform the evacuation.

The Navy enforces a policy of “zero tolerance” against sexual harassment. Would this apply on mixed-sex submarines? Would the Navy literally interrupt a submarine mission and extract an offending sailor if another sailor charged him (or her) with sexual harassment? Or would the commander be forced to handle that situation — on top of all the other critical mission requirements — for the duration of the cruise? What about cases of fraternization? These problems are rare-to-nonexistent in a single-sex environment, but occur frequently when the sexes are mixed.

Finally, it is hard to imagine how an honest cost-benefit analysis would support a decision to redesign and/or refit submarines to accommodate women, even if limited to just a few female officers. Adding space in a submarine means either taking space away from some other vital use, or else lengthening the boat — which radically increases costs. Defense funding should first be spent on training, equipment, better pay — things that will improve the nation’s defense, and not just the job opportunities of a tiny number of women.