Introduction:
The author's acceptance of his approaching death can be attributed to the fact that he was thrown into the sea. This event led to a realization of the imminent danger and the author's subsequent acceptance of his fate.

Explanation:
Thrown into the sea:
The author's acceptance of his approaching death can be directly linked to the event of him being thrown into the sea. This traumatic experience would have brought about an acute awareness of his mortality and the inevitability of his impending demise.

Realization of imminent danger:
Being thrown into the sea would have served as a stark reminder of the perilous situation the author found himself in. The vastness and unpredictability of the sea, coupled with the absence of any immediate means of rescue, would have made it clear to the author that his chances of survival were slim.

Isolated and helpless:
Surviving alone in the vastness of the sea would have made the author acutely aware of his vulnerability and helplessness. The absence of any form of assistance or support would have reinforced the grim reality of his approaching death. This would have further contributed to his acceptance of the situation.

Resignation to fate:
In such a dire circumstance, the author would have likely experienced a range of emotions, including fear, panic, and despair. However, as time passed and the reality of his situation sank in, he may have gradually come to accept his fate. This acceptance could have been a coping mechanism, allowing him to find some semblance of peace amidst the turmoil.

Conclusion:
The author's acceptance of his approaching death can be attributed to being thrown into the sea. This traumatic event, combined with the realization of imminent danger, isolation, and helplessness, likely led to his resignation to fate. The acceptance of one's mortality in the face of certain death is a deeply personal and individual experience, and the author's response is a testament to the human capacity to find peace even in the most dire circumstances.