Sorry about my fail-maths. Despite the animation, it appears that Dragonhide can be dual-cast for a total time of 99 sec. Base: 30s Stab: 45s Dual Cast: 66s Stab+DC: 99s (45s [from Stab] * 2.2 = 99) http://www.uesp.net/wiki/Skyrim_talk:Alteration#Mage_armor_perk_.2B_Master_spell_Dragonhide 2nd-to-last paragraph under that section reads; Dragonhide also cannot be cast while moving, has a long cast time, and can be inerupted. It essentially armor caps the player. Because its duration is so short and its clunky to use, I use ebonflesh 90% of the time at 52 on master. Note in the spell calculations that it CAN be dual casted, despite the misleading animations. When holding both spell casting buttons, Dragonhide jumps to 99 seconds with stability perk. Someone please confirm or deny this, as I've never heard of anyone being able to dual-cast master-level spells, and I just started over on my mage.