Sentence:  The waters grew suddenly lighter, and my spirits rose accordingly. I shouted down to those below that I saw daylight ahead, and a great shout of <WSD>thanksgiving</WSD> reverberated through the ship. A moment later we emerged into sunlit water, and immediately I raised the periscope and looked about me upon the strangest landscape I had ever seen. 
Meaning of the word marked with <WSD> tags:  an expression of gratitude.