Radical 忄
12 strokes
heart 忄 (339a) + catamaran 俞 (756a) = happy 愉
愉快 (403) yúkuài happy; pleasant

He had set his heart on a catamaran so is really happy when he finally gets one. / The fairy comes out in the pouring rain to write the name “Eureka” on the side of the boat with her wand (which fortunately conjures up waterproof paint).