How to reach?
The travel route taken by me was Pune-Kolhapur-Sankeshwar on the NH4 (Pune-Bangalore Highway) and took a right turn under the flyover at Sankeshwar (took a left turn at Sai Hotel just before the Sankeshwar bridge and a right turn under the bridge towards Gadhinglaj). The route is Sankeshwar-Gadhinglaj-Ajra-Amboli (70 kms from Sankeshwar). Sawantwadi is 30 kms. from Amboli and Goa is another 60 kms from Sawantwadi.
Complete route map :
Pune-Satara-Kolhapur-Sankeshwar-Gadhinglaj-Ajra-Amboli-Sawantwadi- Kudal- Malvan (if you want to visit Malvan)-Goa.
Distance in Kms. -- Satara(112)- Kolhapur (123)- Sankeshwar (59)-Gadhinglaj (14)-Ajra (23)-Amboli (33)-Sawantwadi (31)-Kudal (21)-Malvan (30)-Goa (158) = Total - 604 Kms. If you travel directly to Goa instead of via Malvan, the total distance would be about 455 kms.
Preferred route to travel to Goa would be via Amboli-Sawantwadi as the road condition even in rainy season is good.
There is an alternate route : Kolhapur-Nipani-Utter-Ajra-Amboli-Sawantwadi-Goa.
You have to take a turn near Hotel Kaveri for using the Nipani route.
Onward Journey to Malvan and Goa from Amboli:
Took the Amboli-Sawantwadi Road which passes through Amboli Ghats. 3 kms on this route is the Amboli Falls on the main road. It's a treat to watch the water falling from a great height right from your vehicle. During rainy season, you will find a number of smaller water falls on the ghat route. From Sawantwadi you can turn towards Goa (if that is what you are planning) or to Malvan (for Tarkarli, Chivla, Achara, Nivati, Devbaug and other beaches in Devgad, Vengurla and Tondavali). The distance between Sawantwadi to Malvan is 51 kms. But during rainy season, there is nothing you can do at Malvan area including Tarkarli as the sea water reaches the shores and no beach is visible.