Complex sentence: Heesen Yachts was the first Dutch shipyard to employ aluminium alloy for the building of yacht hulls and since then the yard has become a world leader in the design, engineering and construction of high performance, all-aluminium motor yachts.
Split into simpler sentences: Heesen Yachts was the first Dutch shipyard to employ aluminium alloy for the building of yacht hulls. Since that time the yard has become a world leader in the design, engineering and construction of high performance, all-aluminium motor yachts.