Ping.
Malacca Strait is a big time location for pirates. Captains of large freighters run through there fast, heavily armed, and usually try to arrange convoys. Some even arrange for drone aircraft to provide air cover for them to prevent being surprised. I would want a few .50 machineguns at bow and stern, and a few trusted hands on the bridge with M-1 Garands.
It is a good thing that the Indonesian Navy is doing this. On the other hand the pirates can probably bribe elements of the RI Navy to stop ships, to make the merchies more vulnerable to the pirates.