水沉，亦稱“沉水香”，是沉香中密度最高、油脂最為豐盈的品類。其名源於“置水則沉”的物理特性——當沉香內部油脂含量超過約25%時，密度大於水，入水即沉。古人視其為上品，《南越志》記載：“木之心節，置水則沉，故名沉水。”其質地堅硬密實，色澤深潤，香氣濃郁醇厚且穿透力強，是熏香、雕刻與收藏的頂級材料。

Sinking Grade, also known as “Chen Shui Xiang” (sinking-in-water incense), is the category of aloeswood with the highest density and richest resin content. Its name originates from its physical property of sinking when placed in water—when the internal resin content of the aloeswood exceeds approximately 25%, its density becomes greater than that of water, causing it to sink immediately. Ancient people regarded it as a superior grade. The Records of the Southern Yuestates: “The heartwood and knots [of the tree], when placed in water, sink; hence it is called Chen Shui (sinking water).” Its texture is hard and compact, its color deep and lustrous, and its aroma rich, mellow, and highly penetrating. It is a top-tier material for incense burning, carving, and collection.