I put the Spirit Sails 'Mid-size' sail on my Wilderness Systems Tarpon 160i SOT without rudder. It DOES make a BIG difference when the wind is favorable! With the wind directly behind me my kayak will fly. My best speed so far is 6.5 mph as measured by GPS. Without a rudder, it is necessary to make an easy paddle cadence to fine tune your track.
I have used the sail with the winds nearly 90 degrees square and easily got an 'assist', but minor corrective tracking paddling is required. However, the paddling involved was far less effort than would have been required with no sail.
All things considered, it's an easy set-up or take-down. Adjusting the angle is quick and simple, IF the base is within easy reach.
With this 'mid-size' unit, my kayak remains very stable regardless of wind gusts. I have never felt the least amount of instability or any hint of capsize. I am quite comfortable with it. It's simple and effective in the downwind sense. I recommend it. Rudder, or no rudder, it's an excellent, worthwhile purchase.
This down-wind sail rig is a blast. I put one on my Current Designs Pachena and when the wind is right, it’s like getting someone to paddle your boat for you. Using my GPS, I can get 4.5 mph out of a gentle 10-12 mph wind. That’s my normal paddling speed without doing any paddling! Motor paddling gets me to an easy 5.5 mph cruising speed (pretty good for the Pachena). I have been caught in a passing weather front with my sail up an attained a top speed of 8.5 mph - that was one wild ride!This sail rig has a simple set-up and take-down and is very adjustable for different wind directions. You can take advantage of almost any wind abaft your beam with a rudder equipped boat. It also has hands free operation and no lines – this allows you to brace and paddle while sailing, which I feel is the only way to go. The sail design and lack of tending lines means your paddle stroke is absolutely unobstructed. The flexibility of the sail will automatically spill out big gusts of wind, but like any sail, this thing will try to push you over. The extra stability of the Pachena handles this fine, but if you have a tippy boat you might want to opt for the mid-size sail.
Construction, materials and design are first rate. My only gripe is the supplied base is a bit narrow and has to be hand-shaped to fit most decks (due to the deck peak). Not a big deal, but I bought the optional base plate and would recommend this just for the bigger footprint and less hassle. There is a suction cup mount if you are squeamish about drilling holes in your deck – but I haven’t tried it. Other available options include a fishing rod and a light beacon holder.
I don’t want to sound like a commercial for this thing, but it's hard to deny something that gives you an ear-to-ear smile when you use it. Some purists would be appalled, but a sail truly adds a new dimension to kayaking. I've been very pleased with it and give it a 9 of 10 only because I think the optional base plate should be standard.