Why does George Clare go out on to a boat in bad weather to let the sea take him in Part V?

In Part V, George Clare is elderly and sick, and he knows his past might be catching up with him because he receives a letter telling him the investigation into Catherine Clare's murder is being reopened due to the discovery of new evidence. Rather than face the consequences of his terrible actions, he goes out on to a boat in bad weather to let himself be drowned in the sea.