If you substitute "exciting" for "entertaining", I think you'll get what CW means. This is clearly a man who enjoys challenge, novelty, excitement and even a certain amount of danger in his work. I'm sure he'd be bored out of his skull on a ship that simply sailed back and forth and never varied from its routine, so he is willing to risk some danger as long as it's exciting as well (not to mention the chance of considerable financial reward!). Don't forget that that he is understating his exploits to the Musgroves in a very lighthearted fashion here, hardly mentioning the risks at all.