How many hours per week does a marine work?

Depends on the MOS and if he/she is on deployement. I worked for Camp Lejeune Base Legal for a while and averaged 50 hours a week. When I went to work directly for the Base General I was on call 24/7 unless I planned my leave days well in advance.

Meanwhile my infantry buddies got out of work by 2 in the afternoon because they were finished with training already. However, if you are on deployment in a combat zone, you could be working 16 hours a day or more. It just depends on the task at hand. Most non infantry MOS's will be similar to regular office jobs at home on base (7 AM til 5 PM). Hours typically only change for special training or barracks/battalion 24 hour duty which is usually once a month.

All I want to know is Who determines the working hours of those Marines not in a training status; but combat ready during peacetime...and who, at what level on any given base determines the length of time after normal working hours can a Company, for example be subject to remaining on post when they do not have the duty. By whose authority can an entire company be kept day after day (with the exception of weekends) some four to five hours after :normal working hours" and for no apparent reason except to simply just hold them ALL in case some problem occurs?? Someone answer

It really does depend on the MOS and the unit. Average is probably 40-50 hours a week when stateside. You might work some long hours, sometimes, but there is camraderie and a more laid back atmosphere than many civilian jobs. You have a lot more fun, but you also work harder. One thing Marines and other military get that most civilians get are 96's - long weekends, occasionally, and more time off on national holidays that most civilian jobs don't let people off for. Civilian jobs also might offer only 2 weeks of vacation a year, FIRM, but the USMC gives leave time which is accrued differently so you get more time off, too.

Often a 16 hour day with a 4 hour watch every 3 days or so during the 8 hours a day you have left. Sometimes only 8 hours a day with a four hour watch every 3 days or so during your off hours and weekends off except every 3rd weekend you have watches all weekend.

in excess of 40 hours.