ISAF class sailing dinghy : 470
Mackay Boats
- 4.7m 
15' 5"ft
A new hull mould was introduced at the beginning of 2002 in order to incorporate some important modifications to the Mackay shape.
The importance of a maximum beam at the gunwhale in a 470 is very significant. It equates to trapezing power! The wider the boat at the gunwhale, the further out the crew can trapeze and the helmsman can hike. We did some calculations and found that if we increased the beam to maximum, it would give a 70kg crew 2kg extra mechanical advantage. The increase in power would be exactly the same as the crew gaining 2kg in weight. The gains to be made in full trapezing conditions are now well proven and recognised by all crews sailing with the new shape, including the 2002 World Champions.
Max LWL
Any designer will tell you that maximum waterline length is fast. We discovered that improvements were possible in this area at the 2000 Olympics under the extremely accurate templates of the class measurer, Santi. By playing around with various stem profile shapes back at the factory, we further discovered that extending the measurement towards the template by just a few millimetres had the profound effect of increasing the effective waterline length by nearly 25mm. This is huge!
Narrow Bow
Sailing to windward in choppy conditons is a strong point of the Mackay hull. By keeping the bow to minimum tolerance in the bow section, it will cut through the water with less fuss. The boat is not "bounced" by every little wave. Next time you race in a small chop, in light wind or strong wind, take note of the boats that are going fast. Chances are they will be Mackays.
The importance of a maximum beam at the gunwhale in a 470 is very significant. It equates to trapezing power! The wider the boat at the gunwhale, the further out the crew can trapeze and the helmsman can hike. We did some calculations and found that if we increased the beam to maximum, it would give a 70kg crew 2kg extra mechanical advantage. The increase in power would be exactly the same as the crew gaining 2kg in weight. The gains to be made in full trapezing conditions are now well proven and recognised by all crews sailing with the new shape, including the 2002 World Champions.
Max LWL
Any designer will tell you that maximum waterline length is fast. We discovered that improvements were possible in this area at the 2000 Olympics under the extremely accurate templates of the class measurer, Santi. By playing around with various stem profile shapes back at the factory, we further discovered that extending the measurement towards the template by just a few millimetres had the profound effect of increasing the effective waterline length by nearly 25mm. This is huge!
Narrow Bow
Sailing to windward in choppy conditons is a strong point of the Mackay hull. By keeping the bow to minimum tolerance in the bow section, it will cut through the water with less fuss. The boat is not "bounced" by every little wave. Next time you race in a small chop, in light wind or strong wind, take note of the boats that are going fast. Chances are they will be Mackays.
