This is key, pitching the tarp right down to the hammock's SRL. I've done multi-day trips with considerable rain and nastiness with a standard hex (no doors) and it can work ~adequately~ well when pitched low. Some people like the tarp pitched high enough that they can walk in and out without having to stoop, so if you need that sort of clearance and at the same time want storm-worthiness, nothing short of a quonset hut is going to suffice!
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