This webpage says that he did just that in 485 and was defeated.
This webpage says
In the late Spring and Autumn Period (722-481 BC), Fu Chai, the Duke of Wu (present-day Suzhou), ventured north to conquer the neighbouring state of Qi. He ordered a canal be constructed to transport soldiers. This became known as the Han Gou, or 'Han-country Conduit'. Work began in 486 BC south of Yangzhou in Jiangsu, and within three years the Han Gou had connected the Yangtze River to the Huai River by means of existing waterways, lakes and marshes." (Expanded here: The original canal diverted the Yangtze River from south Yangzhou to the Huaihe River in Huai'an via Gaoyou in the north, Sheyang Lake in the northeast and Huai'an in the northwest.)Ancient dating is usually dicey, I know. But am I to assume a naval expedition against Qi ended in defeat the year *after* Fu Chai began building a canal to take him... well, somewhere closer than Qi? Maps of Spring-Autumn confuse me. This seems to be the one everyone uses, but I think it represents the boundaries ca 770. This has later periods represented, but it still looks to me like there's a lot of territory between Wu and Qi.
If I were down in Wu, I think I'd start my conquest of the northern kingdoms with Song or Lu. Which Fu Chai eventually did conquer, IIRC (it's back there in one of those links) by sailing his army up the canal. Just, why start with Qi in 485 and not Chu, a kingdom that marches armies to your borders and that Wu has attacked before? (Chu looks farther away than Chen or Song. I assume you could sail down the river and attack it that way, but it was Fu Chai who built the navy, not Helu and WZX. ) Did FC attack Qi by sea because the canal was taking too long for his imperial patience? And why not attack all the plains kingdoms from the sea and work his way inland, instead of sitting around waiting for his canal to get built?