|Topic Review (Newest First)|
|03-07-2002 06:59 PM|
First of all, ULDB''s are not water ballasted. Volvo 60''s and Open Class 60''s are water ballasted but there is a very big diffference between the way a V60 or OC 60 is water ballasted and the water ballast systems used on trailerables.
To explain, there really are two types of water ballast; movable and what I will call fixed position water ballast. Moveable water ballast is the type of water ballast used by the Volvo round the world ocean racers and consists of a tank on either side of the boat and water is shifted from side to side every time the boat is tacked or jibed. This form of water ballast is typically used in conjunction with a fully ballasted boat. (I personally would love to see this is the type of ballasting system improved and incorporated in production boats.)
The second type has a tank (or tanks) in the bilge and uses water in conjunction with some small amount of higher density ballast. The issue with this type of water ballast is the same as with all forms of low-density ballast. If you compare water to lead, water is approximately one tenth the density of lead. That means you need ten times more volume of water to equal the weight of lead. This means that you will end up with some combination of either:
- The water being higher in the boat resulting in a higher center of gravity and less stability than the lead,
- More water ballast to overcome the higher center of gravity meaning a heavier boat (Remember weight, in and of itself, does nothing positive for a boat and does have a lot of negatives.),
- Appendages that are shaped to hold water rather than to be efficient as sailing foils,
- More dependence of form stability which means a less comfortable motion and a poorer ultimate stability,
- Less interior storage or no sump for bilge water to collect before soaking your clothes.
The bottom line a well-designed water ballasted boat will always be an inferior sailor when compared to a properly designed fin keelboat. As in all things in sailing there are trade-offs. In my book, even if water ballast reduces towing weight (which is questionable since the retractable bulb keel boats do not have to weight that much more than a dry water ballast boat), I really think its too much of a compromise in performance and safety for my taste. There are people who are perfectly comfortable with water ballast, but having been aboard a variety of boats from 20 to 41 feet that have been knocked down to close to 90 degrees, I see water ballast as too much of a risk for my taste.
|03-07-2002 06:10 PM|
With the beam on those ULDB racers around 20 or so feet, having a full tank to windward can provide a lot of torque to keep the boat flat. We hear on the news what happens when they gybe without draining the windward tank... On a MacGregor that''s 6''wide and where you''re not going to empty the leeward and fill the windward tank each time you tack, it''s not very efficient -- its more like sailing around with your bilges full. Though it may be more "stable", it is not fast or efficient. A lifting keel or weighted centerboard would provide better flattening and better performance, generally. If your car can''t pull the weight and you want stability, perhaps a cat or trimaran would be a way to go.
|03-07-2002 08:50 AM|
I agree with you about the fouling but modern ULDB Ocean Racer Design are all waterballasted. Mostly this was done FOR stability and safety when sailing short handed and don''t have 10 pieces of railmeat to assist.
|03-06-2002 06:06 PM|
A lot of manufacturers make water ballasted boats; Hunter, Catalina, MacGregor, Schock to name a few. Like many things in sailing water ballast is a compromise. It makes the boat a little lighter for towing but comes with the high price of sailing performance and overall safety. Also while it works OK for boats that are actually trailered all of the time, there can be serious problems with fouling in the tank of a boat that is left in the water that can result in really awful odors.
|03-06-2002 05:04 PM|
On the small side, the MacGregor 26x is a waterballast/centerboard "motor-sailor"; it is advertised as being able to take up to a 50 hsp motor.
I own a ''67 Westerly 25 heavy displacement sailboat very capable of coastal cruising, I sail inland. A good friend has a Mac 26x, with a 25hsp. We have sailed on both extensively on inland waters. (The Mac has the advantage when it comes to fishing; with the electric trim on the outboard, we have trolled very successfully in shallow waters with the sails down and centerboard up.
The Mac is fine for inland sailing if you want a relatively inexpensive new boat. If you drop the water ballast and "cruise" with the motor, the Mac will plane if you have a light enough load on board. However, be aware, empty the water ballast ONLY in calm conditions. You loose most of the boat stability when the ballast is empty. I know others with the MacGregor who only have a 10hsp. Go with a 25 or more.
My preference is a displacement hull, even if slower. I like the stability, but end up riding out summer T-storms with a sea anchor or under storm sails on occasion. Simply, I don''t have the speed to run for cover.
The MacGregor can run even with the water ballast. It did 13-14 knots with a full five-day load of provisions on board and the water ballast full. It''s a bid tender in brisk winds under sail; a lot of weather helm.
On the other hand, the MacGregor is emminently trailerable (it''s light without the ballast), fairly easy to rig up and launch,and can be moved easily. It not very heavily built.
In short, I wouldn''t own one, but I''ve had one heck of a lot of fun sailing and fishing on one.
|03-06-2002 03:53 PM|
Macgregor is one manufacturer who does a flood balast.
|03-06-2002 12:29 PM|
I am in the market of purchasing a 25 foot or so sailboat. I remember years ago my old instructor said there was a manufacturer that used water as ballast for the keel instead of lead. This made the boat much easier to transport. I can''t remember the name of the manufacturer - does anyone know of this type of sailboat?