The first thing you need to do is see what you’re getting. Add a print_r statement to your php and see what in $images. Post the results.
<?php
$images = get_field('cruise_lines', 'travel-category_74');
for ($i=0; $i<count($images); $i++) {
// the id of the image is in $images[$i]['ID']
$images[$i]['link_url'] = get_field('link_url', $images[$i]['ID']);
}
echo '<pre>'; print_r($images); echo '</pre>';
?>
