Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_38840 ( "Name" text, "Type" text, "Entered service" text, "Water depth" text, "Location" text )

### Question ###
What is the water depth of Sedco 702, located in Nigeria?

### Accurate SQL ###

SELECT "Water depth" FROM table_38840 WHERE "Location" = 'nigeria' AND "Name" = 'sedco 702'