Altough the water is deep the glory of killing Grendel's Mother will be worth it
"He leaped into the lake, would not wait for anyone's Answer; the heaving water covered him Over. For hours he sank through the waves; At last he saw the mud of the bottom."
"All at once the greedy she-wolf Who'd ruled those water for half a hundred Years discovered him, saw that a creature From above had come to explore the bottom Of her wet world. She welcomed him in her claws, Clutched at him savagely but could not harm him."
"She carried him, armor And sword and all to her home; he struggled To free his weapon, and failed."
" Then he realized, suddenly, That she'd brought him into someone's battle-hall, and the water's heat could not hurt him, nor could anything in the lake attack him through the buildings high-arching roof."
"Then he saw the mighty water witch, and swung his sword, his ring marked blade, straight at her head; the iron sang its fierce song, Sang Beowulf's strength. BUt her guest Discovered that no sword could slice her evil skin, that Hrunting could not hurt her, was useless Now when he needed it."
"Beowulf tossed his sword aside, Angry; the steel-edged blade lay where he'd dropped it. If weapons were useless he'd use His hands, the strength in his fingers. So fame Comes to the men who went And care about nothing else!"