Are Eight Hour Watches The Way To Go?

According to this Navy Times article, the Navy is studying if the current 6 on - 12 off watchstanding cycle practiced by Submariners is detrimental to our health and well-being, or if we should shift to something else. Excerpts:
Studies show that even without clocks and sunlight, human biology is best suited for 24-hour cycles. Moving to 18-hour days can create conditions similar to jet lag, said Lt. Christopher Steele, the lead researcher for fatigue issues with the Submarine Medical Research Laboratory in Connecticut.
“It’s like flying to Paris every day,” Steele said of the 18-hour day. “Unfortunately, that results in unpredictable rhythms for alertness.”
Steele and other researchers from his laboratory plan to go on a long-term deployment later this year to study submariners’ response to various sleeping patterns.
Senior Navy leaders will not make any decisions until the study is complete...
...A submariner’s typical day at sea revolves around six hours on watch, six hours of other duties and six hours of sleep.
Previous, shorter studies aboard the ballistic-missile submarine Maryland and the attack submarine Pittsburgh during the past year suggested that dividing a 24-hour day into three eight-hour shifts resulted in better performance, Steele said.
Some more complex three-day cycles were also examined — stacking six-hour shifts, then taking larger 12- or 24-hour blocks off for sleep — were not as successful, Steele said.
Without optimal sleeping patterns, sailors can show lower levels of alertness, limited reaction times or irritability, Steele said...
It looks like they didn't study the effect of "Vulcan Death Watches" practiced during ORSE workups:
Officials with the Naval Submarine Medical Research Laboratory are studying three work-cycle options for submariners:
• 18-hour day: Six hours on watch, 12 hours off (current practice).
• 24-hour day: Eight hours on watch, 16 hours off.
• Three-day cycle: Six hours on, six off, six on, 12 off, six on, six off, six on, 24 off.
So what do you think? On the boats I was on, officers mostly stayed to 24 hour schedules, except for EOOWs during ORSE workups -- and they got every scheduled midwatch off as the "Midwatch Cowboy" gave them a break -- so I never really did the 18 hour days for long periods. Did you notice any detrimental effects from this schedule that weren't otherwise explainable by the normal vagaries of submarining? Do you think this study will result in any changes in the way the Submarine Force does business?