The Osprey Double and Triple Kayak Kits are both light-weight and very stable. They are the same length and beam. The fore and aft cockpits on the Osprey Triple have been shifted to accommodate a third cockpit, which is great for kayaking with kids or for paddling with a dog (see video below).
Osprey Triple Video:
KAYAK KIT Includes: Precision pre-cut BS-1088 Okoume plywood panels(4mm), cockpit coamings, System Three epoxy, measuring pumps, 38" wide fiberglass cloth (6 oz., specially treated for use with epoxy resin) for inside and outside of hull, 1.5" fiberglass tape, wire, squeegee, dental syringes, vinyl gloves, wood flour, stirring sticks, steel push pins, 2-part slung-back rest with a Therm-a-Rest seat pad, Keepers adjustable footbraces, pre-cut temporary frames to aid and ease construction, fully illustrated construction manual.
*The transverse Metacenter, in inches, is a measure of a kayak's initial stability. A higher number is more stable. All single kayaks computed with same weight person.
**Efficient cruising is a function of low frictional drag and low wetted surface (WS). Lower WS means a faster (less effort) cruising speed, here expressed in sq. ft. For example, the shorter Arctic Tern 14 cruises with less effort than the longer AT-17 until the AT-14 reaches 4.91mph.
***Top Cruising Speed (TCS) is determined by loaded waterline length (LWL). A longer LWL gives a faster TCS. At approximately 90% of its hull speed (when a kayak starts to produce a bow wake longer than its LWL) the effort required to continue accelerating radically increases. In general longer kayaks have higher top speeds and short kayaks have more efficient cruising speeds.