Can you be more specific, trinto? Is your proposed voyage a cruise
in which you want to travel from port to port, checking out the people and places as you go, or are you wanting to get to Singapore
as quickly and directly as possible?
If it's to be a cruise
of exploration, then I would guess that you may want to bypass Afghanistan and Pakistan after you clear the Gulf and head
for a landfall on the west coast
, then follow the coastline until you reach the tip of southern India
At that point you can opt for the Indian coast back up to the NE, or head
for Sri Lanka. From Sri Lanka, your nearest landfall would be Banda Aceh (yes, the same Banda Aceh that was devastated by the tsunami) in Indonesia
, and from that point you could follow the coastline along the north side of Sumatra and funnel naturally into the Strait of Malacca.
And, if it is a cruise of exploration, you could cross the Strait and cruise the southern Malaysian coastline as you make your way to Singapore
. You will need to make that crossing at some point anyway to reach Singapore.
The Andaman (or Nicobar) Islands lie between Sri Lanka and Banda Aceh, but India does not welcome cruisers to visit there, last I heard. It will be a long slog, trinto, against the grain (west to east), but if you need to get to Singapore, it beats sailing almost all the way around the world to get there.
PS: Try to obtain a copy of Jimmy Cornell's World Cruising Routes
. Here's a link to the Amazon page: