Dead Sea by Mia Kerick

Kyle is a swaggering bully; Lenny strives to be invisible.
Kyle has been left alone in the world; Lenny is the world’s biggest loner.
When Kyle saves Lenny from drowning, their lives will never be the same.
After a brutal encounter with school bullies, Lenny swims out into the ocean, determined to let the current whisk him away. Next thing he knows the meanest kid in town is pulling him from the waves, promising to be his Dead Sea, and to never let him sink.

All Kyle wants is to get out of beach cleanup, is that too much to ask? So he goes for a swim, only to come upon the most epic “nobody” in the senior class drowning in a riptide. Lenny’s haunted gaze grips him, and Kyle makes the impulsive decision to save his life or die trying. And through this ordeal, Kyle and Lenny are transformed.
Kyle’s heroic act sets him on the straight and narrow, and he opens his heart to the young man he dragged from the ocean. Lenny changes too but is still unable to reveal the truth of his pain. While drowning in a sea of secrets, the reformed bully and wary victim fall in love. But staying afloat in the Dead Sea is not as simple as it seems.

Trigger warning: One character unsuccessfully attempts to die by suicide as is noted in the blurb. There is further discussion of death by suicide.