We both wear the UnderArmor Cold Gear long pants and undershirt under the MK2 one piece. I've never been cold enough to wear the extra coat and sleeves. That includes diving Monterey in 52 water.
I dive SoCal as well and have the Mk2 one piece. But not the extra jacket. I have Under Armor Cold gear tops and bottoms that I was planning on keeping in my gear bag for extra cold dives. My temps are typically 45-65. I have only tried my Fusion in the pool so
I don't know how the mk2 will work for me. From this thread I assume that it will cover most of my diving without having to add the Cold Gear for a base layer.
I have 2 questions, what temps do you think the cold gear alone would be able to handle? and what temps would the Mk2 jumper with the Cold Gear as a base cover me in?
I usually dive pretty hot but for some reason this year I am freezing my butt off. I dove my 7mm with 3mm hooded vest in 60 waters at Catalina and was still cold this year. Last year I was fine in the 7mm alone down to 52 so I don't really know why I am so cold this year. But the good thing that came from it is my new Fusion!!!