Lets get something out the way first. Sleeping in a bivi does require a special type of person. Either you are very hardy and able to cope with claustrophobia or someone who is foolhardy to cope with rolling around in the dark while accidentally trapped inside their bivi because they cannot find the zip in the dark.
The bivi experience is dark, cramped and probably a bit damp so why do I use them?
Sleeping out on top of a hill with nothing but stars above is something you simply don’t get in a tent. You are connected to the land in a greater way than in a tent because you are outside as opposed to inside a tent. I guess that may only make sense to people who sleep in a bivi…
I have used many different bivi options in the past and still own all of them to this day but there is one model I do use above the rest.
The Rab Ridge Raider is a bivi with a waterproof groundsheet and breathable eVent upper as well as having a layer of midge netting to keep bugs out and a single hooped pole to keep the whole thing off your face when sleeping.
Quality and packsize are two of the reasons I keep coming back to this bivi over others time and again.
The performance of the fabrics are exceptional and the eVent breaths as it should and I seldom have any condensation on the inside of the upper but due to the use on a non breathable groundsheet there is condensation that can build up there. Its something I have sadly noticed many times. It sounds pretty bad but this is a side effect of using non breathable fabrics for the groundsheet but the advantage is that its less likely to tear and break because its stronger than the eVent. To get around this issue try to air your sleeping bag and bivi inside out any chance you get.
I also have an issue with its internal dimensions as you can only get a Thermarest Size Regular in there, if you try to use a Large size it puts the whole feet section under tension and so your feet are constantly bent when you are sleeping and when you are spending two weeks solid in one this certainly gets on your nerves… However I did manage to survive and was one of the only people who actually managed to stay dry on this particular expedition.
The upper has never let the water in and because of the midge layer you can sleep bug free without having to close the whole thing. On this subject the eVent is labeled as an exchange fabric this is suppose to mean it will let enough gases pass through to allow the user to zip the whole thing up and not asphyxiate. Definite bonus there.
I am no stranger to the bivi and having been in many other models where rolling over half asleep have closed off the air hole accidentally only to suddenly wake up hyper ventilating I can say that this has never happened in the Rab Ridge Raider. No matter what fabric manufactures say I would always leave a fair size gap in the zip open. The Rab Ridge Raider has a great big storm flap over the zip so you can safely leave a large opening in the zip without water getting in. Fresh air is great to have!
The whole piece packs down to a tiny size with the poles in too and this adds to its versatility as you can just stuff it into your pack and off you go! Ok with sleeping bag and a mat too!
If you are after more protection then you could add a tarp as well. This gives you more space to move around under cover but the Ridge Raider is more than waterproof enough on its own but of course if its already raining you have to get into it first before you are protected! Also not having a place to store your kit beside you out of the rain is an issue with all bivis when used without a tarp over your head.
The Ridge Raider has 4 tent peg holes, 2 on each end. You can keep it place in high winds and this also prevents the material shifting around too much when rolling around at night. This is especially useful if you are a side sleeper.
Life inside the bivi is pretty cramped but this is something you have to get used to. There are 4 zips so you can fine tune the amount of air circulation and where you position the hole too. 2 zips control the bug net and 2 for the outer. Its a great decision that Rab has made these glow in the dark which is fantastic as in some bivis you can literally be trapped inside until you figure out where the zips are.
Overall its a great bit of kit and has stood up to the test of time with only one seam starting to come away on the inside which can be easily repaired. One very noteworthy point is that at least two pegs should be used to create some tension at the head end to keep the midge net taught and therefore against your face. So pack at least two tent pegs!