I think there's a bug in Adventuron. The wetsuit is defined as follows:
wetsuit : object "wetsuit" wearable = "true";
so it should be wearable. It is brought into play as follows:
: swap o1 = "suit" o2 = "wetsuit";
It looks like the swap removes the wearable attribute.
I'll chase this up with Adventuron and see if it is a bug and see if I can find a workaround using create and destroy in the meantime.