This from the former Alpacka Web Site Forum now moved to its own http://www.packrafting.org/forums/:
From the designer of Alpacka herself:
I think it is time I checked in concerning both new developments at Alpacka and aftermarket modifications. I am excited for those of you that are doing mods, many of them are good. However, there a couple modifications that I feel I need to address. More important, I need to address how they’re presented. I’m getting flooded with calls from customers, both old and new wondering what they should be adding to their boats for C-II and C-III water. This concerns me. Most of the whitewater mods I’m aware of don’t have much relevance until you get into Class IV water, or very big Class III. In more normal whitewater, they add weight to the boat, may endanger the boater, and may compromise general boating. I need to call a spade a spade: the boats have been running Class III (and some IV) since 2002 without mods. If you’re running Class II and III water, you honestly don’t need to mod your boat to get reasonable performance.
I will address each of the specific issues individually.
1. Moving your seat forward: This is more applicable with the older boats. The boats that Roman did this with are all model year 2005 or older. Since that time we’ve enlarged and lengthened the stern of the rafts twice, which improves trim and alleviates the need to move forward in the boat . Personally, I don’t see a need to move your seat forward in any of the newer models. If you do want to move your seat, I’d say Velcro is not the solution of choice. It will wear out quickly in that application. I know this because I tried it several years ago. Also, the possibility of sand getting into the velcro in the bottom of the raft where the seat is pretty substantial. With the current thread-in seats, there are much better ways to temporarily move or install a seat.
2. Moving your spraydeck forward: I don’t recommend this. When we have had decks moved forward even a little bit, when the paddler wants to stretch out their legs a large hole is formed between the paddlers waist and the spraydeck. This also tends to pull the deck waist Velcro open. In my experience, it is better to move forward against your deck to get tight in your boat than to have you spraydeck altered forward and never be able to straighten your legs without problems.
3. Thigh Straps: They’re potentially very dangerous. In a word: “entrapment.” Alpacka will not put them in for people, and does NOT recommend them. You can all do this if you choose, but please be aware that there is a very real possibility of entrapment. Reading Tim’s account of getting out of thigh straps drove this home for me. This should not be taken lightly. Packs under a deck can cause entrapment hazard too. I feel we need to caution people that they need to be aware of the risk that they are putting themselves in. Even worse, putting a pack under your knees and then putting your legs into the thigh straps is adding more of an entrapment possibility.
An Alpacka Raft is like a Volkswagon Beetle. The beetle was a magnificent little car that did what it was designed to do. An Alpacka does a terrific job at what it is supposed to do: be a wilderness water access tool. It was never designed to withstand the stresses of rolling and class 5 whitewater. You can put all the attachments on it you want, and as the designer, I’d say you still have a Beetle with forty attachments. It’s not that much closer to the Porsche than it was. A side effect is that you have a 7+ lb. boat. When you need a Porsche, start with a Porche base. Don't destroy your Beetle!
For Class IV and higher whitewater, the kind you’d really want to mod an Alpacka for, I’d say you have two reasonable options: the new boat we’re working on (working title “Witchcraft”) and the a hardshell kayak.
I’ve been mentally designing the Witchcraft for over five years. Everything about it is different and designed to do one thing better: run more difficult whitewater. It’s not a good general trip boat, and isn’t designed to carry weight. This is more of a day creek boat, or a boat for those who want hike in with the objective of hitting a particularly prize piece of water.
Getting back to the kayak point: the Witch will never be as good as a hard shell kayak for high-performance, hard whitewater boating. For that, a molded-hull kayak is the best vehicle. An inflatable improves your portability but doesn’t have the capability to do all the things that a hard shell can. There is a boat for every kind of water, we need to respect and acknowledge how each craft fits into the scheme of the total water picture.
That said, this new boat is addressing many of things that modifications address on older boats.
Design: This boat is designed to be trim with just the paddler in it. The stern has been elongated another 4 inches. The bow tubes have been shrunk down as well. Result: the boat runs really well without a pack and holds its line better than the standard boat, but does NOT carry a pack well. This is much more of a day boat.
Fabric: The entire boat is made of floor fabric to better withstand more serious creek bashing. This throws the weight up to around 8 pounds, maybe more, much more bulky than a classic Alpacka.
Spraydeck: The new spraydeck is drier than the standard one. Several factors are in play here, and be aware that this deck doesn’t work on the regular boats: it does some things that work because of the different hull design. The deck is also glued on, like the floor, and built of much heavier fabric.
Thigh support system: The thigh support system comes from above and when the deck cord is pulled the whole system releases, allowing the paddler to slide out of the boat. What I’m attempting to do with it is create a support system that addresses the dangers I see of thigh straps in the boat.
So far everyone has been very pleased with the new boat, but we are still testing it, and obviously arduous testing is very important for something like this. I’m hoping to make it available sometime in May on a limited basis. We will be taking orders and making the boats up custom for this season. These boats are quite time consuming and difficult for us to produce, so be forewarned that the costs will be higher. I have not costed them out fully because we are still getting our processes worked out but be prepared that the boats will probably be around $300 more than a regular decked Alpacka Raft. I think it will be a great addition to the Alpacka line, but not a replacement in any way for your standard Alpacka, and not a beginner’s boat. This boat is another arrow in your quiver, designed for those of are willing to sacrifice general purpose boating qualities to focus on whitewater. And it still won't do everything that a hardshell can.
Know your limits!
My posts are personal opinions only (not an official statement or policy by Alpacka Raft, although I may allude to existing Alpacka policies).