I was thinking they were for rear tank vents but there are 8 more in the back. The screw holes look like there use to be a plate over them any ideas. Also dont worry about my custom paint job

Vents for what? You know more about my dumpster boat than I do the sides I get its the back ones I dont understand

Thank you lover, I know all about gas fumes the kona had a bow tank, but I have those side tanks, I was going to fill them do you think I should keep them?

Mine is a 71 18' with saddle tanks and my vent is a single hole located in front of the fill cap. 

Beerjet,
the slot louvers vents take a big rectangle hole, not a bunch of tiny round holes. On the back side of them is a flange that sildes into the big rectangle hole. To be honest I'd rather have the little round holes, those big sloted deals suck.

Oh and you are wrong about the gas caps and the vents too. (you said to tell you, lol) One thing doesn't have anything to do with the other. Vented caps allow the fuel to flow to the carb, you either vent the tank or have vented caps. Vents on the side of the hull along with bildge blowers are for removing fumes out of the bildge so you don't blow your ass out of the boat. I've never heard of fumes getting stuck between the gunales and the upholstery before. That's a good one, I'll have to rememeber that. 

Just put some hair around them, suff a blowup doll on the other side, and name it .....
"HUMMER-TIME"
  "I got a problem with my boat Bob, lets drill a shitload of holes in it and see if that fixes her"...By god, I think your on to something there ......get the hole saw and some beer Dick, we have some work to do

Is there some old mounting holes on the inside where maybe an exhaust fan was attached?  it looks a little extreme, Oh wait a minute I just figured it out. There used to be two carbs on it and it couldnt get enough air to feed them so a few more hole later and "WALA" problem solved.
Ok sorry for all the ribbing but as you can see it actually has me thinking and I really can't come up with a logical explanation other than overkill on the venting.
Not that it has anything to do with the holes, but when I first got my boat it had a constant fuel smell, to the point I would hesitate lighting up a smoke at times. It had those polished aluminum flip-latch fillers and although they didn't leak fuel the odor was constant. When I put it all back together, I used different fillers threaded ones that have a small hole in them, I really didn't think letting them vent continuously without restriction would fix anything, I was really surprised when I was out running it one day, and it dawned on me the smell was gone. The problem now is when I am towing it with the tanks full, it'll blow out fuel on the grades or big bumps. But at least I can light up whenever I want to now without fearing a firery death lol

See what I mean, it got me too im not even going to ask about the extra holes in the dash... Maybe there speed holes who knows Ill post better pics tonight. My boat came from a dumpster so its been some work, im just getting to the point where its time to flip it and thats when I plan to fill the holes and make some supports so my shaved bump rail wont crack later on.  Its my first boat and I dont want it to blow up, at least for a while. Daniel

They are probley the worst pictures in the world sorry
You can see that there is a flapper tank cut out but where the tanks would have been there was foam also Omar is the new owner of the front tank I pulled out
Thanks Daniel

What's all this talk of venting the gas tanks?  It's a sealed unit and vented to the outside of the hull. It can be buried under the floor and packed in foam. Besides the fumes coming from a leak somewhere in your fuel system, in which case your're in deep shit and all the little holes in your deck won't do dick, settle in the bottom of the boat, they don't float around and rise to the hightest point of the boat like a foking hot air ballon.

When you vent a tank it's done with either vented gas caps or a thru hull fitting like this... 

my kona has the same holes.. it had some oval shaped chrome pieces with a mesh wire in them .. they are just vents

does it or ever have a enclosed motor?

the above pictured boat is now in ralph and i's posession and it left us both scratchin our heads and thats the best idea we could come up with....that they were vents for an enclosed motor.