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Last season, I installed a passive ballast system on my . I chose to vent the ballast tank through the anchor locker drain (as many have done on this forum) , I installed an electronic monitor, as well as a system to manualy inspect it.

The gate valve started leaking, and I discovered that my ballast was filling while the valve was shut. I think that without a vented ballast system there would be a limit to how much water would seep in based on the air preasure in the ballast tank.

I'm certain that the slowly leaking gate valve would have caused a very dangerous partial ballast stability problem. I have now replaced the valve and consider myself very lucky that I discovered the problem.

I purchased the new valve from Blue Water Yatchs, and installed the outer 2/3 of the valve assembly without replacing the inner plastic portion sealed and installed by the factory. There were 4 screws to the installation as well as using new sealer on the screws.

If you now have a passive ballast system I seriously recommend you check your gate valve for leakage.

Ric K

I think I warned someone about this type of mod in a previous posting. There is no way I would connect the inside of my boat to the anchor locker which traps copious amounts of rainwater and itself drains slowly at the best of times. Rogers design is perfect and the boat will not flood even if you leave both ballast valve and vent plug open unless wave action causes "pumping"

The way to avoid the anchor locker from draining into the ballast tank, is to loop the vent hose higher than the drain hose. It's very difficult to work up in that area but it can be done.

After I completed my installation I tested the anchor locker drain with water under preasure from a garden hose. Nothing leaked into the ballast tank.

If you had a clogged drain it would be above the vent " T " connection so the air would still vent. A completely clogged line would prevent the ballast from draining or filling, that is why my system can be vented conventionaly as well.

Ric K

I'm suprised no one has just fed the fore vent into the cb trunk.
Same thing without any messing around. I'll put a stopcock in the way too so I can purge that last burp out of the front and lock it in place. Stop that sloshing about too!
I'm not a fan of the idea of having an open airway all the time. I'm also fitting a level alarm. I have been known to forget to close a valve and Mrs is convinced that any excuse will turn the boat upside down and we'll die orrible slow deaths like in the Poseidon Adventure...

restless wrote: and Mrs is convinced that any excuse will turn the boat upside down and we'll die horrible slow deaths like in the Poseidon Adventure...

Yeah, maybe, but think of the money your heirs will gross if they film it

Rick Less

Ric K wrote:I think that without a vented ballast system there would be a limit to how much water would seep in based on the air preasure in the ballast tank.

Interesting thought.
I have this habit of opening the gate valve and THEN the vent. I hear water gurgling in before the vent is opened and air bubbles around the gate. The ballast may not completely fill but it will fill without the vent open so I doubt a closed vent will prevent flooding of the tank.

For the record, I still like your idea of venting outside the cabin. The ballast tank get emit some nasty odors through that vent that the humans are left with inhaling.



--Russ

Passively venting the tank through the anchor locker drain is a great mod. As Ric K has indicated, just loop the vent hose higher than the drain hose, and no water from the anchor locker will get into the tank. The only time we have our tank empty [in the water] is when motoring fast, so there's no worry about water seeping in past the transom gate valve and creating a "partial ballast" instability. As soon as we slow down, it gets filled. It's nice to be able operate the valve to fill or empty the tank via boat hook without having to leave the helm, and especially nice not to fill the cabin with "tank smell".

RussMT wrote:I have this habit of opening the gate valve and THEN the vent. I hear water gurgling in before the vent is opened and air bubbles around the gate. The ballast may not completely fill but it will fill without the vent open so I doubt a closed vent will prevent flooding of the tank.
--Russ

It may be possible that if water can leak into a bad transom valve, then air could leak out as well, allowing more water to seep in, creating the dangerous partial ballast problem on a normaly plugged ballast vent.

I would check my transom valve on a regular basis, especialy if you keep the boat in the water all the time, since marine growth could compromise the seal.

Ric K

!	kmclemore:
	Fixed quote.

I am not sure whether others have done this or not but I’ll throw it out there. I moved my vent opening aft to just outside the head door. I purchased a brass double ended male fitting, a ten foot rubber hose and a brass cap. The male fitting was threaded into the tank and 5200ed. The female end of the hose is attached (screwed onto – garden hose style) to the male end in the tank. The hose is run aft and comes out thru the aft end of the ice chest space so that it is facing the cockpit – it is bracketed in and is neat and tidy. I like this mod because it was easy, I can still dip the tank manually when in doubt by unscrewing the hose, I can cap the vent at the tank if I wish (screw brass cap on), I can cap it in the cabin if I wish when the hose is attached (normally do this) or leave it as a passive vent. I don’t need to go forward when filling or draining and I can hear the air being sucked or blown from the tank and the smell is vented quickly out of the cabin with the hatch fully open.

Rod

1997X
Valve under the step.
Easy access, vents quickly due to location, can quickly check the level.

Sometimes newer isn't better

Best thing about the Macs, variations of the mods.

I wonder if you guys who have stinky tanks leave the ballast water in too long. I always drain the ballast and when the boat is on the lift or trailer, I'll crack the gate valve a bit and leave the vent plug open with something holding the cushion up so that air can get in there when the boat is not being used. Good airflow to all sealed sections in a boat is a good idea, I prop my coolers open too so they don't get stinky. Several years later, the tank never stinks when filling.

I always use my boat hook to both open and close the gate valve so I don't have to lift the helm seat. It will start getting sticky once in a while, so as part of my yearly boat maint, I add just a tiny bit of grease to where the valve blade contacts the seal. This keeps it operating smoothly. I always hear of people who have busted off the valve handle, my guess is because they never lubed the valve and the resistance got too high. Also, if you don't lube it, the seal can become malformed and start leaking really badly. If your seal does get trashed (and I think they will last forever with a yearly lubrication), they sell them at any RV store like camping world. Because the Valterra valve used in the Mac is the same as those used in RV sewage water systems.

As was mentioned, the passive ballast vent to the prow, clear vent hose goes up at the very front of the V-berth, only visible for a few inches, then straight up into a u-turn made up of glued angles, so the loop can't collapse, at the very top right under the deck in front of the anchor locker, and then back down to next to the anchor locker drain, where there is a T fitting that joins the anchor drain to the ballast vent.
All turns were done with solid angle fittings, threaded nipples, and glued joints to make secure whenever possible, and avoid bends in the vent hose that migh otherwise collapse. Wherever the clear vent hose is attached to the PVC pipe fittings, use stainless steel hose clamps. It also makes it easier to put the top of the "loop" right up against the deck, without actually having to reach all the way up there, by pre-assembling the two hoses and U-turn fitting.
Even if the anchor locker drain gets plugged completely at the exit hole in the hull, the water will fill the locker and overflow off the deck before it can get up as high as the upside-down P-trap of the ballast vent hose at its highest point under the deck at the very nose of the boat.
At the vent cup over the tank, I drilled a second hole next to the original one, the same size, so it can be plugged if ever needed like the original hole, with a regular plug. In that new hole, a rigid plastic nipple leading into a ball valve, and then a solid right angle fitting,to aim the hose across the top of the flotation under the V-berth. The ball valve and fittings there are also retained by a cross member at the top of the vent cup (the dam), so not to just rely on glue or the fit to keep it in. The ball valve is an added measure, not difficult to install, that allows the closure of the passive vent if extremely rough weather is coming, and it leaving the boat at anchor, or slipped for several days etc.
By leaving the original hole, with the original plug in it, you can still visually check the tank anytime, but for most of the time, the vented tank will take care of itself. However, when first coming back to the boat, after being in the water for awhile, it is easy to check the ballast to ensure it is dry, or filled all the way.
In all I drilled 3 holes in the he boat; the tank next to the original vent inside the dam, in the forward lower bulkhead above the ballast vent but below the liner, and in the liner at the very front of the V-berth, for the ballast vent hose. Except for the few inches at the nose of the V-berth ,the rest of the vent hose is totally not visible in the boat, except by looking into the storage access areas, or up at the nose in the V-berth in front of the anchor locker.
Three years now since the mod, and no problems, no problems anticipated.
If you have guests below, no need to move them around to check and open or close the vent, the several times usually, and it is WAY better if single-handing to not have to leave the helm to deal with the vent.

This isn't quite on topic, but I think it's related:

During some of the zebra-mussel discussions, last year or the year before, I seem to recall that someone had installed a screw-in deck plate into the "dam" around the vent hole on his ballast tank. This was to permit the "mussel police" to hose out the ballast tank with hot water, and kill any mussel larvae that might have been picked up in the tank during a visit to contaminated waters. Anyone else remember that?

I'm finally squared away to do some traveling with Bossa Nova, and I figure I'd better be prepared to decontaminate the ballast tank to the satisfaction of any Natural Resources Police where I'd like to float my boat....

A boat that has dried for 5 days or more will be considered safe by most states here...maybe its the same for you??