Not sure why bushwalk.com rotated my photo. Oh well.
The RAB Latok Ultra Bivi is a recent addition to the RAB lineup. It replaced the Summit Ultralite and whilst similar in many ways it has some significant improvements. Although called a bivi by RAB or a bivy by others, this is really a tent. I'll mix up these terms in my review purely to annoy the reader.
Like its predecessor, the Latok Ultra is made from 3 layer 15D eVent fabric, with totally waterproof 70D coated nylon bathtub floor, the sides of the bathtub are somewhat higher on the newer model. The floor area is the same at 120cm x 220cm, but the headroom has increased from a claimed 70cm to a much more friendly 80cm although I measured mine internally at 85cm. A pleasant surprise.
Other notable differences are a change to a bottom "hinged" door instead of at the side, the rear tunnel vent is higher up allowing for it to direct a breeze above the occupants head, fewer guy points and peg down points now four of each instead of six, and finally a colour change to bright yellow.
The added height being the biggest change, as well as making it a proper sit up inside tent it has reduced the steep angle of the walls creating more useful interior space.
Unlike the larger Latok Mountain, they don't offer the option of an add on vestibule. But a small triangle of sil-nylon, a trekking pole and tie points to the belay donut at the peak and the two front stake points should provide a weather protected entry and cooking space for only a tiny additional weight. I should be able to knock that one together.
This tent is actually a product of the Colorado company Integral Designs where it is marketed as the MK 1 Lite Bivy. Their website has more technical information about the tent than the RAB site and they even have a downloadable instruction manual. Something that RAB don't seem to think necessary.
The bivy itself weighs 1kg with the guy lines attached. The two DAC featherlite poles add 340g and the eight DAC pegs another 80g. This is significantly lighter than the claimed 1.6kg total. The minimum weight therefore being only 1330g. It could also be used as a double bivy without the poles and guys at less than 500g per person, if one was so inclined.
Although this is meant to be a two person tent, I have no intention of inviting anyone to share this tiny space with me (except my wife of course). But it does make a very comfortable space for one plus all the gear necessary for an extended snow trek. I set it up next to a well used Bibler I-tent and discovered that the RAB actually has a larger floor area. This particular I-tent has accommodated five large blokes when all the other tents in the group failed. A good testimony to the basic design of the I-tent that RAB have effectively copied and some would say improved upon.
I purchased this tent through the UK store Rock + Run. It arrived via courier just a few days after placing the order. The tent was on sale at £262.50, I bought a couple of other items from them so the postage, although expensive, was spread over several items.
So far I have used the tent for only three nights this winter. One night reached a chilly minus ten. But alas no snow exposure yet. It will be interesting to see how it performs in snow and in some more exposed locations as its maker intended. Stay tuned.
. Odd that its rated 3 season, I guess not much mountaineering happens in winter 
