We took the Frankston-Baxster trail to the Peninsula trail and then rode on the wide shoulder of Frankston-Flinders Rd to Sommerville where we could get on to the Sommerville to Hastings section of the Western Port Trail.
We stopped for coffee at Pelikan Société in Hastings and then rode through Warringine Park on the boardwalk to Wooleys Rd (which didn't have a shoulder and was 80km/h but really quite) and on to Stony Point Rd (which also had no shoulder but was pretty quiet) to catch the Ferry to Cowes on Philip Island with 5mins to spare.