as a starter to the sport the deepest ive done is about 6 foot but before i turn my box on i have a good listen around and then turn my box on and home in on it but i was talking to my old man about this and he said for years they never had a locator and they said they got on fine with using a bar but i could never leave my house with out a locator but i was just speaking too a man from up yorkshire he repairs the old deben boxs ive just sent mine up to him but he said hes got all the parts to start making a the old deben boxes again but hes gonna make them to go to 20 foot soo when i get one