Whether one is looking to buy an inexpensive tent for their kids' first camping adventure or a top of the line model which will endure several seasons' worth of hard use, a tent's perceived ability to withstand the elements is at the heart of the purchasing decision.
As a water proof tent's claims cannot be put to the test on the showroom floor or an internet page, what should the savvy shopper be looking for to choose the best waterproof tent within their budget?
There are two popular styles of nylon tents on the market today--single wall and double wall. The very best waterproof tents available today are single wall designs, but they are expensive. Single wall tents depend solely upon the tent body itself to protect against the elements. This feat is managed by the use of expensive nylon panels with special, and usually proprietary, silicone based coatings. This combination allows the tent walls to both repel water from the outside and allow the moisture from one's breath or other evaporates to escape through the tent's fabric to the outside.
Every seam on these tents will have been carefully sealed with heat applied taped that bonds over the seams. The tent's mesh windows will all have zippered covers to be able to adjust the ventilation level. These tents are customarily the products of expedition level manufacturers--for mountaineering use or extreme backpacking--where weather resistance, light weight, and ease of set up under difficult conditions are not just niceties, but could be the margin between life and death.
Since single wall tents are out of the budget of most shoppers, double wall tents dominate the market. In this design, when executed properly, the two parts of the best waterproof tents available handle separate parts of the waterproofing challenge. A double walled tent will have a nylon and mesh body, and usually features a tougher duty nylon based floor with a "bath tub" look to it that goes part of the way up the walls.
A better designed tent will have minimal or no floor seams at all and any floor seams present on the tent will be "taped" against leakage through the needle punctures made during sewing. The untreated nylon walls will have mesh windows, doors with both materials, or perhaps the body above the floor may be made entirely of mesh to save weight. Most of these tents will not feature totally sealable windows as the best waterproof tents are designed with nearly automatic moisture management in mind.
The second part of the double wall system is the fly, which mostly separates the well designed tent from the lesser ones. Usually, the most waterproof tent will be the one with the best fly coverage. This part is often treated with a non-breathable coating to better shed water than the nylon itself can manage. Think of the fly as the tent's "umbrella."
The better the coverage provided by the fly, the drier the tent is likely to remain under rainy conditions so long as adequate ventilation is maintained. A great fly will also provide one or even two covered areas outside of the tent body, called vestibules, where rain soaked gear can dry out while not being inside of the tent. The best waterproof tent will have a fly featuring both vestibules and collapsable ventilation scoops built into them.
However, a fly that provides total coverage must be well matched to the tent body to ensure that it does not trap condensation on the inside at its highest point. Trapped moisture will cause the tent to "rain" upon you from the inside. Beware the tent that has a full coverage fly but lacks generous interior mesh to provide an airy feeling. If you can spend a few minutes inside a floor model, close it up if you can and just lay there. If the tent gets stuffy or feels warm, it does not "breathe" adequately. It is the task of a sleeping bag to keep you warm in a double walled tent. The best waterproof tent's job is to keep you dry against both the rain and your own breath.
Finally, no matter how attractive the price, consider rejecting any tent featuring an abbreviated fly that will inevitably allow water to pour onto some part of the tent body. A tent that allows its non-coated walls to encounter continuous moisture will leak the moment the fabric is touched and stressed from the inside. A tent that you can foresee either leaking or raining condensate due to its design shortcomings will almost certainly come to ruin a camping trip the first time it is relied upon against adverse weather.
The best waterproof tent for you is the one that brings as many of the features described above as meets your budget, size requirements, and the type of trip you are planning.