We started from Pune at 5:30 in the morning. The best route in my opinion is to take the Pune Satara highway and drive till Umbraj (A village 17 kms before Karad).
Upon reaching Umbraj, one has to take a turn to the right from under the flyover. This road leads to Koynanagar & further to Chiplun. Chiplun is approximately 98 kms from Umbraj. The road is in an excellent condition with hardly any traffic. The drive is simply amazing with canal from Koyna dam on one side of the road and lush green trees on the other (even during the month of May).
On the way one has to cross Kumharli ghats (approximate length of road in ghats : 12.0 kms). The ghats are very easy to negotiate. Once you descend the ghats, the road joins Mumbai - Goa Highway near Chiplun.
Upon touching Mumbai - Goa Highway, one has to take a left turn and start driving towards Ratnagiri. After approximately 72 kms from Chiplun, one reaches Nivali (Approximately 18 kms before Ratnagiri). To reach Ganapatipule, one has to take a right turn from Nivali Phata and drive for 32 kms. This road too is in an excellent condition with hardly any traffic.
We covered the distance of approximately 341 kms in about 8 hours with two halts : One at Umbraj and the other at Chiplun.
The excellent condition of the road, along with scenic beauty does not allow you to get tired of driving.