CREATE TABLE table_name_31 (tyre VARCHAR2, entrant VARCHAR2, rounds VARCHAR2)

Name the tyre for hb bewaking team ensign with rounds of 13
SELECT tyre FROM table_name_31 WHERE entrant = "hb bewaking team ensign" AND rounds = "13"
SELECT "tyre" FROM "table_name_31" WHERE "13" = "rounds" AND "entrant" = "hb bewaking team ensign"