If you want to start an argument among sea kayakers, bring up rudders, paddles, or … ballast! Admittedly, not as many megabytes of online space are devoted to the latter as to the first two, but the controversy is just as heated. The arguments go as follows. Pro: Boats are more stable when full of camping gear and the Inuit put rocks in the bottom of their qajaqs so add some ballast if your boat is too tippy. Con: If your boat is too unstable, either get another boat or improve your balance skills.

I have the kayak review from Sea Kayaker Magazine for my old boat – a Perception Sea Lion - and the graphs make it patently clear that adding gear will dramatically improve the boat’s stability. Quantitatively, if I’m just sitting in my boat, it takes a sideways push of about 9 foot-pounds to tip me by 10^o, but if I had 100 pounds of gear in the boat with me it would take 20 foot-pounds to tip me by the same amount. Actually, even without the geeky numbers and graphs, a little common sense will tell you that adding weight low in the boat (like the keel on a sailboat) should make it more stable.

I love my boat and I can fit about anything into it that I could think to bring along for a multi day camping trip, but the boat can be a bit tippy when loaded with just my lunch, binoculars, and a water bottle when I’m out for a day trip. I’m not willing to risk the stability of my marriage just to have a second smaller more stable boat for day trips, so I have decided to try ballast. A little reading lead me to the following design criteria: The ballast needs to be removable so it doesn’t need to be lifted to the top of the car along with the boat. It needs to be centered and as low as possible to symmetrically lower the boat’s center of gravity. It needs to be well secured so that it doesn’t replicate the well known instability of a cockpit half full of water. Finally, it needs to be somewhat aft to improve the boat’s weathercocking and broaching tendencies. What I settled on was two 6 inch pieces of 3 ½ inch PVC pipe filled with #5 lead shot (one 25 pound bag from a gun store) and then sealed with PVC caps. Conveniently my boat has a metal rod to which the seat is attached and this provides a place where I have attached webbing straps to buckle around the PVC to secure it.

I’ve been using this ballast system for a couple of months now and can report the following: The boat feels significantly more secure without my paddle in the water as I watch birds through binoculars. I am much more secure in those squirrelly situations of paddling with aft-quartering wind and waves. I can’t tell any difference in the paddling difficulty of hauling along an extra 25 pounds of weight.  Finally, my daughter thinks that I perhaps have rocks in my head for putting rocks in my boat.

So, I agree that nothing beats practicing your balance skills at every occasion, but I’m also convinced that a little well-placed ballast will noticeably improve the stability of an empty boat that is designed to carry a lot of cargo. 

 

Comment posted by jaegs on Tuesday, July 21, 2009 5:29 PM I like this.  I've often wondered about adding ballast while kayaking in the Apostle Islands with an empty kayak.  The uneven wave action keeps you on your toes or I should say hips.  Is there a formula that would help determine the optimal amount of ballast for a 200lb paddler?