he now had a companion, an audible companion

[esteven]

There were plenty of people on the little quarter-deck- the master at the con, the quartermaster at the wheel, the marine sergeant and his small-arms party, the signal midshipman, part of the afterguard, the gun-crews, James Dillon, the clerk, and still others - but Jack and Stephen paced up and down as though they were alone, Jack enveloped in the Olympian majesty of a captain and Stephen caught up within his aura. It was natural enough to Jack, who had known this state of affairs since he was a child, but it was the first time that Stephen had met with it, and it gave him a not altogether disagreeable sensation of waking death: either the absorbed, attentive men on the other side of the glass wall were dead, mere phantasmata, or he was - though in that case it was a strange little death, for although he was used to this sense of isolation, of being a colourless shade in a silent private underworld, he now had a companion, an audible companion.

(chapter four)

I always felt this was the first time that showed how together Jack and Stephen are, even this early on.
*smiles*

Spreading himself comfortably along the locker

[esteven]

And some of them are very mere rakes," says he, piercing me through and through with that damned cold eye of his,' said Jack, filling Stephen's glass and spreading himself comfortably along the locker

(chapter four)

I should not be surprised, having read through the books several times, but it continues to amaze me how very early we find quotes of the slashy kind. I mean, first getting Stephen to loosen up by filling his glass and then spreading himself. I am sure the doctor took the hint

Stephen sans breeches

[heather_mist]

"(Stephen) went to his cabin below, his mind still somewhat confused by happiness, and found that in spite of  everything Killick had laid out all the clothes that were proper for him to wear.  He slowly dressed, taking  particular care of the set of his coat, and came out into the gun-room where he found Pullings, sitting carefully in the gold-laced splendour of a commander. ..

'Now, Doctor,' Pullings went on, 'it is time for me to run an eye over all; and perhaps for you to put your breeches on.'
'God save you, Tom,' cried Stephen, looking with concern at his pale bony knees. 'I am so glad you noticed it. My mind must have wandered.  I should have got the ship a worse name still.'  "

(Nutmeg of Consolation) Chapter 10.

Dear Stephen! He never has much thought for his clothes at the best of times, and having just heard of the longed-for birth of his daughter, it is the furthest thing from his mind now. Thank heavens for Tom Pullings.

The Infamous Brown Knitted Garment

[heather_mist]

"And as Stephen rose to wave and hoot, Jack saw that he was dressed from head to foot in a single tight dull-brown garment; it clung to him, and his pale, delighted face emerged from a woollen roll at the top, looking unnaturally large.  His general appearance was something between that of an attenuated ape and a meagre heart....

'Mr Simmons,' said Jack, fixing him with a hard, savage eye, 'this is my friend Dr Maturin, who will be accompanying me.  Dr Maturin, Mr Simmons, the first lieutenant of the Lively.'
'Your servant, sir,' said Stephen, making a leg: and this, thought Jack, was perhaps the most hideous action that a person in so subhuman a garment could perform....

Jack got him into the after-cabin at last... here he sat on a locker and gazed at Stephen's garment.  It had been horrible at a distance; it was worse near to - far worse...
'Stephen, will you for the love of God take off that thing?'
'My wool garment?  You have noticed it have you?  I had forgot, or I should have pointed it out.  Have you ever seen anything so deeply rational?  See, I can withdraw my head entirely: the same applies to the feet and the hands.  Warm yet unencumbering; light; and above all healthy - no constriction anywhere!  Paris, who was once a framework knitter made it to my design: he is working on one for you at present' "
Post Captain Ch. 12

Words Fail Me. 
*facepalm*