I'm arriving in Douglas 6.30am ferry on Friday 3rd June. Any suggestions for a decent breakfast at that time in the morning around Douglas area.

I would go to The Caff, or The Buttery both do a great breakfast and not far from the terminal. 👍🍵🍟

Second that for the caff, go left out of the terminal and up Lord Street past the car parks.

Harry's Cafe, in Douglas, cheap (TT cheap-ish anyhow) and cheerful.
If you're heading to Ramsey call in Shoprite, they do great Breakfast Buns.