1. As the study shows, boarded cats point higher with less side-slip. On keeled production cats you can “stick them up into the wind” but they tend to crab horribly when pinched – you must crack off considerably to reduce leeway and sustain momentum. 2. Typically, the draft on keel cats is deeper than on dagger-board cats. Our 526 keel version draws about 300mm more than the dagger-board version. Some cats carry very stubby keels to sustain shallower draft, but the shallower the keel the poorer the close-hauled performance. 3. Off-the-wind with the boards raised 75 percent there is less drag and the boat steers and sails faster and more playfully. 4. As the study shows the dagger-board cat is a bit faster and makes less leeway on nearly all points of sail in the majority of wind conditions. 5. An equally efficient set of keels has almost four times more wetted surface than dagger-boards, as is the case on our 526 keels. 6. Set properly, dagger-boards can assist in preventing a cat from a ‘tripping capsize’ in very high winds with large, breaking cross seas. Both boards can be fully raised, or only the leeward board raised, so the boat can sideslip easily. 7. Dagger-boarded cats tend to have a slightly higher resale value because few are massproduced. A buyer wanting boards tends to focus on cats that have them.