What was the water depth that entered service in 2001 named Cajun Express?
CREATE TABLE "ultra_deep_water" (
  "name" text,
  "type" text,
  "entered_service" text,
  "water_depth" text,
  "location" text,
  "customer" text
);
SELECT "water_depth" FROM "ultra_deep_water" WHERE "entered_service"='2001' AND "name"='cajun express';