Concluding report:
The gaiters were fine, but our three night four day stay in Zamami felt extremely short and the beaches were fascinating to all of us, our hiking off of maintained main roads ended up being extremely minimal. A scientific survey was being conducted on parts of the island which meant we got to see a huge swathe of the local land fauna, but, alas, the little creatures were stuck to squares of adhesive. It was a tough lesson for a child on where scientific data actually comes from. We didn’t see or disturb any habu.

But I did come across two venomous snakes on Zamami. Twice I came across surfacing sea snakes. The black and white striped kind. Was guiding my non-swimmer father-in-law on his first (last?) snorkel safari when the second snake started surfacing from under us and managed to pull him away without freaking him out or getting water in his breathing tube. Thankfully he never even saw it or realised what I was doing.
Am definitely returning, so will keep the gaiters. Zamami is a paradise.

Just looked through a set of photos MrLapLap took from our trip last month.
Within the pictures were some he took when he accompanied LapGirl and his father (but not me) to Takao San.
Including one of this local inhabitant which crossed their path. Slowly enough for him to get a shot.

Having looked through some reference sites, am pretty sure it’s a Ratsnake (Elaphe conspicillata). Also called a Tiger Keelback.
Not venemous.

It’s the Mamushi or Pit Viper (Gloydius blomhoffii) that needs to be backed away from at Takao San.