And because they don't have actual captains, they are ridiculously difficult to capture. A boarding party from a French dragon can only hope to kill some of the crew but neither Laurence nor Temeraire would really be capable of being captured with the threat of hurting one person.

"At worst he's an acid-spitter... she thinks. She didn't know he was French, never looked at his lovely family chart." Oh yeah, she miscalculated. ;) She thought that she was going to humiliate him, have him turn into some low-bred dragon so everyone can see how low he really is... ;)

That's a good point about Temeraire's egg. I believe it was justified because they were trying to be secret. Also, generally the trip IS faster and less dangerous by sea than by dragon (Laurence only didn't wait at the beginning of Black Powder War because their ship had suffered an accident and needed months to be repaired), and a dragon transport ship isn't exactly subtle. ;) The Frenchmen on the ship had been in the doldrums for over a month and were running low on supplies, too. :(

"It would still find Laurence and that would be the end of it, but it's much thornier when it's the dragonet meant for the emperor and has decided that it's sleeping in the brig." Now that would be an interesting situation, if the egg imprinted on someone who was a prisoner of war! ;)

I think that they never intended the egg to hatch on board a ship: it was bound for Napoleon himself, remember? (Also, Napoleon was apparently notorious for not having a head for naval battles. He was all about land engagements. So he wouldn't be on a ship. ;) )