WHAT ABOUT THE WEIGHT
When multi-fins first arrived on the scene there was quite a bit of trial and error going on. Some production runs would appear much heavier than others, then the slot-box was introduced to save weight and it couldn’t really withstand the strains of windsurfing so there was much hesitation amongst the brands.
However, naturally with time the latest developments in slot-box materials and the screws utilised have become much much stronger and still light weight. It’s pretty fair to say that these days the slot box is as strong as the US box and is more than capable of withstanding the every day forces of windsurfing. As a result the weight of a board is kept within the reasonable margin and thus the 5 fin boxes have become yet even more attractive.