I think this is heathrow to Columbia then Columbia to Mumbai then Mumbai to Goa.
You can also do Columbia to Cochin (kerela) then up to Goa via train.
I think we may investigate this next year as always wanted to go to Kerela and Sri Lanka and this could prove very cost effective.

Already discussed - look here. Clicky

As Max states this has already been discussed but I'll just add here that I know a few people who have flown this route without any problem. The best thing about this option from my point of view is that Air Lanka are part of Emirates so you can earn skywards points!!
GFF xx

Very interested in this route, had a look at Air Lankas web site but not much luck with it. Who's best to book with re the overnight stop in Colombo etc? I.m always keen to boost my Skywards miles ! Alan

Hi Alan,
Not sure about booking from the UK - maybe give them a call directly.
If you are booking from this end your agent will sort everything out - the Free acomm is standard so is automatically applied to your itinerary when you book. The Air Lanka office in Panjim also take bookings and the staff are very helpful. Currently there is no facility to book flights from Goa on-line.

I've added a link for contact detaills in the UK, hope you get something sorted.

GFF xx

http://wwi.srilankan.aero/contactus/sla-offices.asp?officeid=10144

Thanks very much GFT for the info, I'll certainly look into it. Alan