The sentence you are referring to is a play on words - puns in any language are difficult for non-native speakers. The real sentence is "his bark is worse than his bite." This means that "he makes a lot of threats but does not follow through," a reference to a dog that barks a lot but does not really bite. In this particular case, Horatio Hornblower is a Royal Naval Officer in a series of novels by C.S. Forester. "Barque" is a type of vessel (ship), and "bight" is a type of knot, and sailors are known to tie all sorts of knots in order to secure their ships. So the one-sentence book report is a very clever play on the idiom "his bark is worse than his bite" and the nautical terms "barque" and "bight." As a protagonist, Hornblower is also a reserved, self-doubting character despite his extraordinary skills. Therefore, saying that his "bark (barque) is worse than his bite (bight)" may be a good summary of this fictitious character. I hope this was helpful.

"His barque was worse than his bight" is an antiquated spelling of the expression "His bark was [is] worse than his bite." It refers to dogs that make very loud and threatening noises but actually aren't dangerous at all. It's often applied to people who seem more dangerous than they actually are.

There is an English proverb that says "His bark is worse than his bite" When a dog barks too much, it doesn't bite. So the proverb means that someone is not as unpleasant as he/she seems to be. Your classmate used "barque" instead or "bark", and "bight" instead of bite. This intentional distortion of the proverb is no doubt a wordplay. That's why she got an A. Check in a dictionary the words "malapropism", "pun" and "spoonerism" to see what I mean by wordplay.