bubble out meaning in English

勃突勃突地涌出

I will confess that i was far too much taken up with what was going on to be of the slightest use as sentry ; indeed , i had already deserted my eastern loophole , and crept up behind the captain , who had now seated himself on the threshold , with his elbows on his knees , his head in his hands , and his eyes fixed on the water , as it bubbled out of the old iron kettle in the sand
我得承认，我被正在发生的事情完全吸引住了，压根没起到一个警戒哨的作用事实上，我已经离开了东边的射击孔，趴在了船长的后面，这会儿他正坐在门槛上，肘拄在膝盖上，用手托着头，注视着从那只旧铁锅底的沙中冒出的水。