not think there are no crocodiles (just) because the water is calm

/nˌɒt θˈɪŋk ðeəɹˌɑː nˈəʊ kɹˈɒkədˌaɪlz dʒˈʌst bɪkˈʌz ðə wˈɔːtəɹ ɪz kˈɑːm/

/nˌɑːt θˈɪŋk ðɛɹˌɑːɹ nˈoʊ kɹˈɑːkədˌaɪlz dʒˈʌst bɪkˈʌz ðə wˈɔːɾɚɹ ɪz kˈɑːm/

not think there are no crocodiles (just) because the water is calm

used to emphasize that even in seemingly safe situations, people should be aware of potential dangers and threats