I pulled from the SealFit SOF workouts today.  I was in the mood for a long grind full of bodyweight work.  I found what I was looking for:

Complete as many rounds as possible in 30 minutes of the following…

50m Weighted walking lunge (use any weight you have access to) We mostly used 45-60 pound sandbags

20x push ups

20x 4-count flutter kicks

*At the 15 and 30 minute mark, stop what you are doing and run 800m or row 60 calories

This one was simply a grind.  Good mental toughness training as it was quite boring as well.    I would definitely say that this one will definitely not go on the list of favorites or even one that I might return to, however, the work was valuable and was reminiscent of a Goruck event, 20 x or Kokoro.  Just endless, mundane, routine bodyweight and ruck work designed to grind you physically and mentally.