Complex sentence: The Hornet is a restricted class meaning that its external hull measurements, sailing weight, sail measurements, and mast dimensions and weights are controlled, but the hull's interior layout, centreboard and rudder have few restrictions.
Split into simpler sentences: The Hornet is a restricted class meaning that its external hull measurements, sailing weights, sail measurements, and mast dimensions and weights are controlled. However the hull's interior layout, centreboard and rudder have few restrictions.