Compound adjectives ending in <worthy> have the main stress on the initial element. Notice also that the pronunciation of the ending is wɜːði. Here are some examples:
airworthy ˈeəwɜːði
newsworthy ˈnjuːzwɜːði
noteworthy ˈnəʊtwɜːði
roadworthy ˈrəʊdwɜːði
seaworthy ˈsiːwɜːði
2013_08_22