CO exposure DD vs Vdrive
 

Is there a difference in hazard level here for the rearmost passengers, seeing that they are closer to the exhaust?

Thanks

In my DD before I got FAE people would complain sometimes when we were just idling because the fumes would come up between the swim platform and the rear of the boat. A Vdrive would make a difference as you are sitting that much further from the rear of the boat.

I would think that the closer you sit to the exhaust the more exposure you would have but it has to do with the year of the boat now too. Most of the newer boats have catalytic converters (other than the supercharged bad boy engines) and fuel injection that both help to reduce emissions. Supposed to be like 90% less now than boats with carburetors and no cats from 15+ years ago.

I assume your talking about while surfing. Just normal cruising any exposure to passengers should be minimal. You may have more when idling, but underway at cruising speed you should have very minimal exposure.
Now if your surfing and have the boat listed, there is the "station wagon effect" which can get more CO into the passenger compartment. It isn't too noticable, but a FAE is able to remedy this in any boat.
+1 about EFI and catalytic converters. Those minimize CO before it even comes out of the exhaust a lot.

I've found that any boat without a CAT system can be plenty bad but, yes, I've found D-drives to be worse if you're sitting in back. Even with a CAT system, I would install an FAE. It's just too damn nice with it on there not to put one on.

Yes, there is a difference. A D-drive gives you more exposure at the very rear seats than a V-drive. It's also louder at the back seat. Put on an FAE and the world is better. If you are at idle you still have some exposure at the very rear of a D-drive unless you are in forward gear.