▁These ▁pod s ▁and ▁the ▁trim ▁van e ▁were ▁intended ▁to ▁provide ▁additional ▁fl ot ation ▁and ▁stability ▁on ▁the ▁water ; ▁they ▁provided ▁virt ually ▁no ▁additional ▁arm our ▁protection . ▁Other ▁changes ▁included ▁a ▁modified ▁driver ' s ▁h atch ▁which ▁p iv oted ▁toward ▁the ▁centre - line ▁of ▁the ▁vehicle ▁instead ▁of ▁opening ▁to ▁the ▁rear ▁of ▁the ▁driver ' s ▁h atch ; ▁this ▁feature ▁prevent ing ▁the ▁open ▁driver ' s ▁h atch ▁being ▁caught ▁on ▁the ▁travers ing ▁tur ret , ▁as ▁well ▁as ▁the ▁fitting ▁of ▁the ▁British ▁" bo iling ▁vessel ", ▁an ▁electric ▁vessel ▁for ▁bo iling ▁water ▁and ▁he ating ▁r ations . ▁As ▁indicated ▁by ▁the ▁design ation ▁change , ▁the ▁MR V s ▁were ▁ro led ▁as ▁reconna issance ▁vehicles ▁and ▁issued ▁to ▁the ▁Caval ry ▁( medium ▁reconna issance ) ▁reg iments ▁with ▁each ▁tro op ▁equ ipped ▁with ▁ 3 ▁L R V ▁and ▁ 2 ▁MR V ; ▁whereas ▁the ▁F SV s ▁were ▁originally ▁issued ▁to ▁A PC ▁squad rons ▁and ▁used ▁to ▁provide ▁inf antry ▁fire ▁support . ▁The ▁MR V ▁replaced ▁the ▁F SV ▁in ▁Australian ▁service . ▁ ▁M 1 1 3 AS 3 ▁- ▁significantly ▁upgrad ed ▁M 1 1 3 A 1 ▁with ▁new ▁engine , ▁transmission , ▁ste ering , ▁susp ension , ▁bra kes ▁and ▁h ull ▁protection . ▁ ▁M 1 1 3 AS 4 ▁- ▁upgrad ed ▁to ▁the ▁same ▁standard ▁as ▁the ▁AS 3 , ▁length