Why did Arthur Philip decide to move to Port Jackson two days after arriving in Botany Bay?

Question

This wikipedia article on Botany Bay suggests the following reason:

Governor Arthur Phillip sailed the Armed Tender Supply into the bay on 18 January 1788. Two days later the remaining ships of the First Fleet had arrived to found the planned penal colony. Finding that the sandy infertile soil of the site in fact rendered it most unsuitable for settlement, Phillip decided instead to move to the excellent natural harbour of Port Jackson to the north.

I have always been intrigued by the decision to move as Port Jackson is not so far away from Botany Bay.

To this day there are not many buildings on the north side of Sydney Harbour, most of the settlement to my understanding was built near Farm Cove which is hardly a trek from Botany Bay.

So was the poor soil the real reason for moving to Sydney Harbour or where there other more important reasons?

Answer 1

It is easy to view the distance between Botany Bay and Port Jackson as small by today's standards, but it is actually a considerable 'trek'. Even with todays excellent roads, it takes two and a half hours to walk from Circular Quay (and the better soil around Port Jackson) to the northern edge of Botany Bay.

Then consider you have to carry supplies over multiple trips and this short distance becomes a great deal longer.

But the most important point is indicated in the Wikipedia article:

excellent natural harbour of Port Jackson to the north

A deep, well protected harbor was incredibly valuable to a new colony that would rely on support and contact with Britain to survive and, in the long term, trade to prosper. I imagine that the proximity of such a harbor makes Phillip's decision even easier.