The meaning of "twice too much at that"

Question

Sulinor rubbed his wrists again. 'We were towing our longboat half-full. I steered somewhat that day.'

'What sail were you showing?' Baeticus demanded.

'Nothing--and twice too much at that. But she came round when Sulinor asked her, and we kept her jogging in the lee of the island. I said, didn't I, that my girt-hawsers were on deck?'

This is from "The Manner of Men" by Kipling.
https://ebooks.adelaide.edu.au/k/kipling/rudyard/limits/chapter19.html

I do not understand the meaning below.

What sail were you showing

and

and twice too much at that.

I am glad if some one would kindly teach me.

Answer 1

It is clear from a previous paragraph

... the full north-easier stamped on us! Run? What else? I needed a lee to clean up in.

that they were running from a storm (although there seems to be a typo: north-easier for north-easter).

So the question

What sail were you showing?

asks how much sail was being shown to the wind — was being used.

The next paragraph

Nothing — and twice too much at that. But she came round when Sulinor asked her, and we kept her jogging in the lee of the island.

means that no sail was being used — but even that was too much and the ship had enough motion to be steered without using any sail.