Yes, anyone who's been to Lahaina knows that it's still a small town, and can probably imagine how crowded it got. Q's estimates are a bit off however. According to Starbuck, the largest number of American ships working the North Pacific in one year was around 300 in 1846. As we have determined, this was before the ships entered the Arctic Ocean, but were working in the areas South of the Bering Straits. The biggest year of Arctic whaling was 1852 during which 278 American ships were working the N. Pacific. The entire worldwide American whaling fleet in those years was around 700 ships. Of course there were also French, German and English whaling ships, but not in huge numbers.
The Sandwich Islands News of Sept. 30, 1846 provides a list of all the whaleships that called at Lahaina from July through September, totaling 94 vessels. Of course this still would have made Lahaina very crowded. For example in late August 1846, there were at least two dozen ships anchored at Lahaina at once. At an average crew of 30 men per ship that's 720 rowdy whalers running around that quaint little town.
Not all of the North Pacific fleet would have stopped in Lahaina at one time, because, as Q points out, there were other ports in the Hawaiian islands at which whalers called, primarily Hilo and Honolulu. The fact that whaler's try-pots have been found all over the islands (really all over the Pacific) does support this fact, but it's important to recognize that all trying-out (rendering) was done at sea. The pots were left ashore at the end of the voyage, to lighten the ship's load as much as possible when whaling was done. These were, in some cases, used by islanders in small shore-whaling ventures, or were repurposed for other uses.
One notable event in this history was the loss of 34 vessels, out of around 70 working the Arctic grounds, in 1871. Though the ships were crushed in the ice, the long time during which the ships were stranded allowed for all hands to be rescued. As a result, around 1200 whalemen ended up stranded in Lahaina and Honolulu, trying to find new ships. It was really the last hurrah for the Arctic whalers, and the Hawaiian newspapers of the day describe the chaos created by that many bored whalemen in town all at once.