I picked up this little guy for around $150 on my first bicycle trip in 2008. Since then I have taken it up and down BC, along the U.S. Pacific coast, across the continent, twice, and down to Mexico for a few months. If you know nothing at all about hammock shelters, you should probably do a quick search for more info. The basic Hennessy Hammock, is a regular hammock with bug netting on top and a silnylon fly over that. You string it up between two trees and climb in through a Velcro flap on the bottom. For some reason you don't fall back out of this flap. I am not sure why. Should you buy one? I don't know, but here was my experience.
The fact that I used it through 160 nights means that it wasn't terrible. The first thing to consider with this hammock is the weight. It is less than 2 lbs, which brings you into the realm of ultralight when it comes to shelter. Your alternatives at this weight are some pretty expensive small tents, cozy little bivy sacks. or sleeping under the stars on the dirt, yugh. Whether or not you need something light weight is up to you.
So how does it perform? In terms of comfort, I never had a bad nights sleep because of my position in this hammock. It is no tent inside, but you have a foot or two of open air around your head which helps with claustrophobia. You can probably sit up if you are short. Like you will read all over the place when you search "Hennessy Hammock", you lie kind of flatish inside. If you stick your feet to one side, and your head to the other side, you are cradled like a candlestick resting in a dish towel that you hold by two opposite corners. I know, terrible analogy, but those were the only things I could see in my kitchen. This is as opposed to the backyard hammock which treats you like a banana, crimping your head up at the end. Unless you are rigid like a candlestick, you will still sag a bit in the middle. I would say something like 15 degrees of difference between the angle of your head and your feet. I have two herniated discs, and it didn't bother me. Some people say it is like sleeping on air. I can't really tell because sleep is sleep to me.
This brings me to the big downside in terms of comfort though. The cold. You absolutely need to have some kind of foam or inflatable insulation underneath you with this hammock. Even on mild summer nights, having a draft under your bum will keep you awake and shivering. I spent a few weeks of June in the single digits (Celsius) with a summer sleeping bag huddled in the fetal position and shaking all night. Being up in the air just exposes you to more wind overall. You can counter this a bit by hanging the hammock as low as possible, setting a steep fly angle and by considering the direction of the wind and what will block its path.
High winds also cause other problems for this hammock. This fly is really light weight, and comes with some pretty thin guy lines. A bit of strong wind can easily lift the whole fly and snap the lines. This actually happened to me out in Kansas during a thunderstorm. It was a soggy miserable night. I suggest having some parachute cord along with you in case you need to make repairs. It is useful camping stuff for a lot of other reasons too. If there isn't much wind though, the thing is very waterproof. I never got wet on calm nights, even in heavy downpours. It's nice not having to deal with water runoff too.
Overall, the construction has a few weak points, and high winds will exacerbate these. All of the lines are pretty thin. I suspect this was how they shaved down weight on this ultralight model. I can't speak for the regular size Henessey though. I have snapped and retied the fly guy lines about a dozen times and since replaced them with paracord. I have also snapped both of the elastic lines that pull the hammock sides out towards the fly The plastic hooks that hold the fly ends onto the main line bent and broke in the wind. The "tree hugger" webbing straps eventually became cut through from having cord cinched through the loops. The ridge line that goes down the middle of the hammock snapped one night when I sat down in the hammock. I retied it with my own cord, but the length of this one is really important because it sets the tension of the hammock. The mosquito netting has gotten torn in several spots. This one is really the fault of my dog who I let into the hammock when he was a pup. I patched the holes with duct tape and a sewing kit. Lastly, the siltarp has gotten seriously stretched in the middle, so it sags even when pulled tight at all the corners.
Okay, so that last paragraph sounded pretty damning, and I guess it is for some people. I don't really mind fiddling with my gear and making field repairs a bit. Nothing broke until after the first two months of use if that makes it sound better. The hammock still works today, and I would take it on solo trip this summer if I needed it.
The one thing I still have to talk about is set-up. If you are on your own, out in the forest, this thing really shines. Finding two trees isn't really hard. A lot easier than finding level ground for a tent. It takes a bit of practice to judge how far apart the trees need to be though. The "snake skins" that should come with your hammock are really brilliant. They let you roll your hammock up into a big tube. You can just string up the tube, then slide the skins off and unroll your hammock. This is great for keeping everything dry while it's raining. You need to be a bit careful when you attach the fly to your hammock. It is not symmetrical, and there is a right way to do it and a wrong way to do it. Make sure your fly is attached the right way.
Here is my set up usual set up sequence: Find a space with two trees and throw the rolled up hammock onto the ground. Tie one end to a tree with a bowline. throw the other end around a tree at the same height and pull it tight. Put a slip knot or overhand knot in to keep it there. Unroll the hammock and peg out the fly corners. Go back to the second end, and pull it tighter (because opening the hammock always loosens the lines). This time lock it off with a figure of eight hitch (Basically just keep wrapping it back and forth around itself) and finish off with a slip knot. That's it
I set up quite a bit in places where there were no trees around. This basically turns your hammock into a bivy. You can see one such setup below. I used my bicycle seat to prop up one end of the fly. I had the front brakes locked and the whole set up was very stable.
So to conclude, I think the best environment for this hammock would be forest, jungle, around valleys and lakes. Worst place you could take it would be the arctic tundra.
PROS
- light
- easy to set up
- keeps the rain out
- more space than a bivy
- kind of flaky construction
- sucks in the wind
- less space than a tent