I've flown Singapore and Malaysia to Australia on many occasions, its water below all the way and it does share a maritime coast.
But does the aircraft fly straight without any turns or angles in the line of travel? I didn't see such a straight line on the map. (Doesn't mean there aren't any such straight lines of travel- I may have looked at the map wrong. I didn't see any that didn't cross land, though.) Edit to add- I looked at Singapore specifically, not Malaysia.
All aircraft turn, but it is a fairly straight journey over sea. Boat journey does not bump into any bits of Indonesia.
That's not even remotely a straight line! LOL Per the OP rules: I challenge you to take a ruler and that map and draw a straight line from Singapore to Australia without hitting land belonging to another country. You could almost do it, if your line went through near Bali ... but not quite. 'Tis a moot point now, though. From Ceylon (Sri Lanka) to India. India (Mysore): gold fanam of Tipu Sultan, AH 1200 (1786), Patan mint PCGS MS62; population 1 - the only example certifiedby PCGS as of 11/21/2018.
I'm not sure where to play from with that! Starting from the "maybe China" point, I'll travel north, to ... Russia (Imperial): 1/4 kopeck (Polushka), 1900, ICG MS66 RB. KM/Y47.1, copper. St. Petersburg Mint.
Okay! Playing off Uzbekistan, I'll take us to Kyrgyzstan with this with this here 2008 5-som. She's been chewed on the reverse but she's decipherable.