( ( Such vessels ) ( ( ( are currently ) ( required ( to ( ( ( exchange ( their ( ballast water ) ) ) ( outside ( ( ( ( ( the ( 200 ( nautical-mile Exclusive ) ) ) ( Economic Zone ) ) , ) ideally ) ( in water ) ) ) ) ( ( ( ( at least ) 2,000 ) meters ) deep ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Such) (NNS vessels)) (VP (VBP are) (ADVP (RB currently)) (VP (VBN required) (S (VP (TO to) (VP (VB exchange) (NP (PRP$ their) (NN ballast) (NN water)) (PP (IN outside) (NP (NP (NP (DT the) (CD 200) (JJ nautical-mile) (NNS Exclusive)) (NP (NNP Economic) (NNP Zone)) (, ,) (ADVP (RB ideally))) (PP (IN in) (NP (NN water))))) (ADVP (NP (QP (IN at) (JJS least) (CD 2,000)) (NNS meters)) (RB deep))))))) (. .)))
Such vessels are currently required to exchange their ballast water outside the 200 nautical-mile Exclusive Economic Zone, ideally in water at least 2,000 meters deep.
(ROOT (S (NP (DT The) (JJ photic) (NN zone)) (VP (VBZ extends) (ADJP (NP (CD 200) (NNS meters)) (JJ deep))) (. .)))
The photic zone extends 200 meters deep.