This is something the submariners celebrate. It is the calculated half way point on their cruise. They will normally have a large dinner consisting of Tenderloin, lobster, shrimp, and a special desert.

Surface ships will normally keep to a semi set schedule that is known to the crew. A submarine crew will not have general knowledge of its cruise until underway. Sometimes only the captain and a few others will know the actual details of a cruise, such as length, so halfway night is a calculated event. Most of the time the captain will let everyone know when it is halfway.

We had dinners like this as well, but it was mostly done when we had a major change in our schedule. During Med1-92 we had this happen. Our wonderful port visits for the month of December were all cancelled and we went straight to the Red Sea. So we had a killer dinner.

So, that difference between the surface and sub fleets. One gets a killer dinner to celebrate. The other gets one because we are about ready to get bad news.