rslifkin
Guru
- Joined
- Aug 20, 2019
- Messages
- 7,584
- Location
- USA
- Vessel Name
- Hour Glass
- Vessel Make
- Chris Craft 381 Catalina
My boat has the unfortunately all to common engine room vents in the hull sides. The blower discharge vents are low profile and aft facing, which has never presented a problem. The issue are the vents placed for natural draft ventilation and air intake. They're only about 3.5 feet above the waterline, and the forward set are fairly far forward and also forward facing (vents are the same as the ones in the picture).
I've ripped slats out of them a few times, although I've determined that I can avoid that by just pulling them all and upgrading the tiny tack welds that hold the slats.
The bigger issue comes when running in any kind of steep, choppy seas over about a foot where we're throwing a lot of dense spray (not the light stuff that just gets blown onto the boat, but the heavy magazine cover photo walls of spray), it's fairly common to get enough spray pushed up and along the sides of the hull to start taking some water down the forward vents. It's never been enough water to cause any real concern, but the limber holes from the outer portions of my engine room aren't quite perfectly placed, which means I have to mop up some leftover water any time it happens.
Currently the hoses come out of the bottom of the collector boxes in the hull sides. I'm not sure I can get good enough access to those areas to determine if I could flip them to come out the top and make a U bend downwards (that would likely keep most of the water out). So I'm considering building dorade boxes of sorts at the top of the engine room. Hose from the vent would come into the box with another hose coming out higher up to continue down to the lower part of the engine room where the current hoses terminate. The boxes could then be drained to a thru hull so the water just goes over the side. If I were really going crazy, I'd change it to all intake on one side of the hull, exhaust on the other rather than the "both on both sides" it has now, which is less than optimal.
Any thoughts on that method of catching the water? Would it possibly reduce airflow enough that I'd want to add another pair of vents?
I've ripped slats out of them a few times, although I've determined that I can avoid that by just pulling them all and upgrading the tiny tack welds that hold the slats.
The bigger issue comes when running in any kind of steep, choppy seas over about a foot where we're throwing a lot of dense spray (not the light stuff that just gets blown onto the boat, but the heavy magazine cover photo walls of spray), it's fairly common to get enough spray pushed up and along the sides of the hull to start taking some water down the forward vents. It's never been enough water to cause any real concern, but the limber holes from the outer portions of my engine room aren't quite perfectly placed, which means I have to mop up some leftover water any time it happens.
Currently the hoses come out of the bottom of the collector boxes in the hull sides. I'm not sure I can get good enough access to those areas to determine if I could flip them to come out the top and make a U bend downwards (that would likely keep most of the water out). So I'm considering building dorade boxes of sorts at the top of the engine room. Hose from the vent would come into the box with another hose coming out higher up to continue down to the lower part of the engine room where the current hoses terminate. The boxes could then be drained to a thru hull so the water just goes over the side. If I were really going crazy, I'd change it to all intake on one side of the hull, exhaust on the other rather than the "both on both sides" it has now, which is less than optimal.
Any thoughts on that method of catching the water? Would it possibly reduce airflow enough that I'd want to add another pair of vents?