The following data came
from a couple of local fishing books and reports from the
Western Pacific Regional Fishery Management Council but, one thing you should know is that fish don't
know how to read calendars. 
Like party guests, they don't always show up
when they should and sometimes they still hang around when they're supposed to
leave. The best fisherman in Kona will alter their target species with what will
give you the best chance of a successful fishing day. I have the best catch rate
of any charter captain in Kona every year since 1997 by doing it this way! 
If I'm
already booked up, I refer captains/boats that have a higher than average catch
rate.
Further explanation: Kona is the Pacific blue marlin capital of the world and is one of the most common of catches here. An average boat catches an average of 1 in every 4 days. The way this average works can be misleading. When the bite is on, you might catch one or more daily. When the bite is not happening, you might not see a marlin for a whole month. A good marlin run can happen for a short period of time any month of the year. Striped marlin are rare in the summer months but not unheard of. Black marlin are a rare catch with only around 20 caught a year here. Sailfish show up from time to time also. Spearfish show up in big numbers and are one of the best eating fish there is. Mahi mahi can be caught year round as can ono but use the chart above for peak season(s). In the summer, yellowfin tuna can hop on your line any time you're trolling but in the off season, they travel with the spotted dolphins (commonly called a porpoise school) so any time of year you run into this situation, there's a chance of catching 100+ lb. yellowfin. Small (under 15 lbs.) yellowfin and bigeye tuna are common around the fish aggregation buoys in the winter. The "big" bigeye tuna ones are an uncommon catch here. Skipjack tuna are the most common fish we have. At under 10 lbs., they're considered a bait fish. Once they reach the 10 lb. + size, they are called "otado" or "otaru". If bled out and properly iced down, they're a good eating fish. Especially when they reach 20 lbs. or more. Amberjack, almaco jack and sharks are the most common fish caught near and on the bottom year round. All of these are hard fighting fish. Giant trevally and some other kinds of trevally are more rare. Snapper and grouper are more of a bycatch while going for the jacks. I hope this information is useful to you. You can always check out my fish Photos Page to see what I've caught lately and my monthly Kona fishing report has a ticker-tape style update that I try to update about once a week.
