It’s always common to have two bilge pumps: A small one down on the bottom of the boat and a really big one up a little higher. In the powerboat world they do this so that small leaks or occasional water gets pumped out by the small pump slowly with little electric draw. In a REAL emergency (like a hull breach) where your primary (small pump) is overwhelmed and water gets up high enough to reach the second pump it’s a WHOOSH and the water is all gone and you can maintain flotation as long as you have electricity.
Now, this is not my idea – this is standard practice in the stink boat world and the reason the large pumps are up high is to avoid clogs. All the dirt and crap is on the bottom where the small pumps are. You don’t want to lose your big pumps in an emergency – so you protect them. This is standard naval architecture.
In the case of our M boats the recommended primary pump would be 500 to 1000GPM and the secondary 2700 to 3500GPM.
As I was reviewing my old naval architecture books, Chapman’s, etc. . . and designing the layout and schematic for the new pumps going into ‘boat’ it occurred to me that the LARGE pump would be a GREAT WAY TO PUMP OUT THE BALLAST!!.
Don’t you think it would be cool to pump out the ballast in one big WHOOSH before beaching or at a dock or other times?? I thought it would be cool.
Why not add another large hose leading to the ballast tank with a valve? It just seemed like a convenient thing to me.
I guess if you were in a big hurry there would be an advantage, usually we just secure stuff on deck while the ballast empties using old mother natures gravity gift.
Yeah, I am also trying to think of why this would be a good thing. In what circumstance would I want the water out of the ballast where I would not just run the motor for a few minutes??
I'm trying to find reasons why. I hate to see that secondary big pump just sit there with nothing to do all the time.
In the very small harbor we have here in Oceanside there is not a lot of room to run the motor very fast and it's more fun to sail to the ramp anyways. I just thought it would be nice to pull up the ramp empty.
I dunno - I thought it might be useful but then all the people here would have thought of it already. It could be a dumb idea.
BOAT wrote:Yeah, I am also trying to think of why this would be a good thing. In what circumstance would I want the water out of the ballast where I would not just run the motor for a few minutes??
If you're aground or shallow-beached and don't want to wait for the tide to turn to push off.
It might come in handy if you are about to hit the trailer and didn't dump out prior to (rough water, exposed ramp, or just plain forgot). I tow with a mini-van, so dumping the water out before pulling out the trailer can help, but sometimes getting the boat on the trailer is tricky, full ballast helps navigate.
dont know if I would want to be on the boat with a partially filled ballast while it is pumping out. Maybe while its moving foward, but it would come out anyway under power. Been brought up before..either pumping it out, or forcing air in to displace ballast water. Its the half full time that is the most dangerous. I sure wouldn't sail without ballast. it is quite tender motoring after launching when empty while its filling. even if it were done, the taxing on the battery just before pulling out wouldn't be worth it.. either be flattening the battery, or close to it for that kind of volume of water with our tiny group 24/27 batteries.
also, in an emergency, with a big pump, you are only buying some time before the battery gives out. We don't have big batteries on board that can pump a big pump for a while, keeping up with the flow from a hull breech. A true emergency requires a high volume manual pump somewhere in the system in addition to any electric bilge pump. still be difficult to keep the water pumping out faster than it is coming into the boat. At least these boats won't go to the bottom like our 38' would!
Yes, good ideas! Pumping ballast might be nice just before beaching the boat or right after?
Captain taime has a good one too - here in our little harbor in Oceanside it's so small you can't run up the motor to get speed. You're forced to go out to the outer harbor where a wake is allowed and go in circles. That's kinda lame. It's always nice to go up the ramp with no ballast.
Taime - with all foils up and ballast empty my boat drifts around with the wind real bad. In the crosswind here in Oceanside I must point to the farthest RIGHT dock to drift into the farthest LEFT dock!! I do that only when I'm too lazy to put the foils back down after emptying the ballast (another good reason to pump?) USUALLY after I run out the water under power (foils up) then I put the foils back DOWN to get to the dock. That makes even an empty ballasted boat behave pretty well.
I'm trying to think of any other reasons to pump the ballast. I hate just wasting all this pumping power I will have laying around here.
taime1 wrote:It might come in handy if you are about to hit the trailer and didn't dump out prior to (rough water, exposed ramp, or just plain forgot). I tow with a mini-van, so dumping the water out before pulling out the trailer can help, but sometimes getting the boat on the trailer is tricky, full ballast helps navigate.
I always go on the trailer with the daggerboard sligtly down, rudders down, ballast full. once on the trailer. open the ballast valve and vent, pull up on the ramp to let it drain. close the valve, refloat it if it didn't load just right, then pull out. takes a bit longer but seems to work well. Just don't leave the DB down too much or it will hit the trailer frame. The foils do give it a lot of control getting it on the trailer.
"either be flattening the battery, or close to it for that kind of volume of water with our tiny group 24/27 batteries."
Indeed, and the main reason that most salvage companies claim sailors use for not having a bilge pump. You need to think like a stinkboat operator at that point. Those guys live or die off thier bilge pumps - if you in a hull breach the first and most important thing on a power boat is maintaining engine power. It would be the same for us in the M - you need to keep that motor running in an emergency. That's standard practice.
Read recomendations from salvage companies - contrary to what many think, sailboats are salvaged off the bottom just as often as power boats. The salvage companys will tell you WHY the boats went to the bottom in the first place.
It's true the M should be okay because of flotation but I'm old school (back when boats had lead ballast and went straight to the bottom if breached).
I believe some have considered or implemented a ballast pump. Wakeboats have been doing this for years, although they generally use "sac" or bladder type tanks.
One reason a Mac owner installed a pump was to lift the boat off a grounding. Empty boat draws a couple less inches of water. *shrug*
It's very difficult to actually pump all the water out as the design requires the boat to be tilted up to drain it all out the transom valve. A little water sloshing around in the ballast tanks is a dangerous situation.
Bilge pumps are an interesting topic. The Mac M doesn't have any shaft logs or thru hull fittings to leak. Any water in our bilges generally comes from rain water leaking from topsides someplace. If you have seawater in there, I'd be concerned. There is no real bilge either. There are compartments that are low and collect rain water, but no real bilge, so where do you put a pump? Doesn't stop Mac owners from creative pump placement. I've seen some clever ideas that pump from one compartment to another to a "master" pump that discharges overboard. A sponge takes care of mine.
An emergency high cap pump then becomes a talking point. Again, we don't have normal stuff that cause leaks that need emergency pumps like shaft logs, thru hulls, rudders or keel bolts.
So what's going to put a hole in your boat that you need a pump? You hit something like a rock. Well that usually occurs close to shore and you can hop off and cling to the rock, swim to shore. Even still, our boats generally bounce off of things we hit without holing them. Maybe a log or pole at high speed, that would do some serious damage. Probably more damage than any pump could keep up with. The Mac has flotation and most of us would end up clinging to a capsized hunk of fiberglass in the end. I've done some research and not found any that have ended up like this. Amazing that tens of thousands of these Mac out there and few sink or capsize.
That 2,000gph pump will keep up with a 1" hole okay at 15 amps. But a 1" hole is pretty small for a hull breach. A 2" hole in your boat will introduce about 8,000gph.
So if you want to invest time and money on a high cap pump (2700-3500gph) then go for it. Make sure you run heavy gauge wire to it (10), they draw a lot of power and make sure the exhaust hose is high up, has a check valve and is big (1 1/2"). At that rate, I'm not sure it would keep up with a fiberglass breach.
I've known powerboaters who had shafts pulled out when they ran aground. Pump helped keep up after they stuffed junk into the hole.
If I were inclined to have an emergency bilge pump, I'd make it portable. Get a big fat pool hose and heavy 10 gauge power cable with battery clips. Then if I had an emergency I could clip it directly to the batts, run the hose over the side and dunk the thing into the source of incoming water. A handheld VHF is a good idea because in whatever situation got me there, I'd need help quick.
I don't have a bilge pump, I keep my insurance paid up, PFDs close and inflatable dinghy ready and stay away from rocks.
Well, if it's only for emergency use (like when grounded), why not just rig up a Coleman air foot-pump to push air into the vent valve? Would not take much pressure, just volume.
A big ass pump wont pump for long though .. probably give you enough time to find a place to beach it however. Even with the motor running, no way would the tiny OB alternator keep up with the power loss of the battery getting flattened.
for the way most of us sail, it is probably not needed to have a firehose volume pump. If it is..then need to get a battery bank that would make the titanic proud! LOL! Most of us won't drop a grand or 2 for a edson manual pump!
Any rain water, leaks I just use a 1 gallon wet/dry vac to clean up when we get home. Never been a problem
Paul S wrote:I always go on the trailer with the daggerboard sligtly down, rudders down, ballast full. once on the trailer. open the ballast valve and vent, pull up on the ramp to let it drain. close the valve, refloat it if it didn't load just right, then pull out. takes a bit longer but seems to work well. Just don't leave the DB down too much or it will hit the trailer frame. The foils do give it a lot of control getting it on the trailer.
Everyone has their favorite way to do it.
Yup
I used to hit the ramp with empty ballast. As noted, the boat has little hull in the water and wind blows it all over.
So now I go full ballast, full rudders (with line loose) and dagger down. First mate is ready at the daggerboard line to pull it up just before we hit the trailer. It works well. If the rudder hit (they don't) they will kick up. Just remember to pull them up (and tilt motor) before pulling the boat up the ramp.
Once on the trailer, just pull up a few inches and open the ballast gate valve. Wait a few minutes and all the water drains right out. Easy.
I did learn to put a few chlorine tabs in the ballast tank as emptying a month's old ballast water stunk up the ramp pretty bad.
I think Russ makes all the good points why a pump is not really needed. All my sailboats were sailboats only with little outboards. I think the fact that the M hauls ass at 22 miles per hour is making me a little more worried than I need to be?? The air pump would be great too if all I needed was to pump out water on a sandbar or somthing.
I get around the Channel Islands off Oxnard and all I see are rocks and very few boats to help me if I run over a log or a piece of Japanese Sunami debri. It's fun to beach it there.
I dunno, Like I said - I was looking for ideas. I think the one idea of putting the big rule 3700 on jumper cables with a portabl hose is a GREAT idea because you could always stuff an intake hose in it and stuff that down the ballast vent. The portable output hose is a great idea. It just might be a nice piece of hardware to have on board.
Thanks for the ideas - you have all helped me greatly.
RussMT wrote:It's very difficult to actually pump all the water out as the design requires the boat to be tilted up to drain it all out the transom valve. A little water sloshing around in the ballast tanks is a dangerous situation.
I agree with Russ. In order for the ballast tanks to be drained completely, the boat needs to be angled bow up (such as on a trailer or powering) so that all the water can find the gate valve. If the bow is not angled up, a partial ballast situation may occur which is VERY dangerous due to sloshing. Even if we were to solve this safety problem, using a bilge pump requires a liquid prime to pump the water out. This would require cutting into the ballast tank and finding the lowest spot near the transom gate valve to install the bilge pump. This alone would deter me since emptying the ballast tank with air from the vent hole is a far more simple and elegant solution.
