I have taken many a long ride on my Speedmaster and have had several seats on the bike. My wife bought an AirHawk inflatable seat cushion and I wish I had just bought one of them to begin with. I could have saved a lot of money and sore butt hours.
They are a fantastic cushion that is also easily removable in seconds.
Check them out AirHawk cushions

A word to the wise is not necessary. It is the stupid ones who need the advice. Pat