Overpowered Cat?

[SteveInMD]

The last thing I want to do is start a mono vs cat thread. My question is how to tell when a cat is starting to be overpowered. I have chartered cats a number of times and I have found it difficult to tell when to reef based on the feel of the boat. On a monohull it's pretty easy... the rail is close or in the water, the weather helm is to a point where the rudder is close to stalling and the boat is nearing the point of rounding up. Is the decision to reef a cat based only on the apparent wind speed?

I'm asking the question so I can improve my cat sailing skills, not to try to argue one side of the cat vs mono debate. I am trying to spend some more time sailing a cat so I can decide for myself cat or mono for some future long distance cruising, but that decision will be my own and it won't be decided in this thread. So, I'm really looking for cat sailing pointers!

[belizesailor]

You get very little physical or visual feedback on the typical cruising cat. Many I think "sail by the numbers" like I do. Depends a bit on the boat, but generally 20 knots apparent is a good point on many to pull in that 1st reef in the main (main sail driven sail plans on most so reefing main has biggest effect). Similar to a mono you wont lose much boat speed when you reef appropriately.

Unlike a mono, you dont typically get increasing weather helm....by the time you get noticeable weather helm, you are already way over canvassed.

Keep an eye on the stern hulls. Windward will ride higher. Leeward deeper. As you get to know the boat, you will become atuned to small changes in trim between these hulls as an indicator. Flow off hulls and wake also become a good visual for speed thru water. The wake will change as your speed does. I can usually judge boat speed within a knot or less just by looking at the wake...at 7 knots on my boat, the wake goes smoother and narrower....above that I start paying more attention to sail plan and wind. Wake of course will be wider on leeward hull than windward...a very skinny wake leaving the windward hull could also indicate time to back off.

Watch your bows too. If you start getting significant spray over leeward bow...its time to back off.

With a mainsail driven plan, depowering the main has the biggest effect. So, in gusty conditions keep the mainsheet close at hand and be ready to dump it (controlled of course).

[thinwater]

The BEST way to learn about this is to sail a small boat (dinghy or beach cat). Push them to the limit and learn the symptoms of when things are about to go pear shaped. And what to do about it.

Would you give a $300,000 truck to a driver that had never ridden a bicycle or driven a car at least 50K miles? I doubt it.

Start small, even if you have to go back to the beginning and rent something for a few afternoons. Or go out some local beach cat racers.

---

I've sailed a lot of cats, and other than watching for the windward hull getting light (much of it coming out of the water when going to windward) or a bow burying (down wind), there are no general rules about helm or AW. There is feel, but it is subtle.

The only simple rule is to never carry more sail off the wind than you can carry up wind. You can, of course, but trouble can follow when you try to reduce.

[belizesailor]

Originally Posted by thinwater

The BEST way to learn about this is to sail a small boat (dinghy or beach cat). Push them to the limit and learn the symptoms of when things are about to go pear shaped. And what to do about it.

...

Yes, a good way to learn...and flipping a beach cat can be fun! A cruising cat...not so much.

[44'cruisingcat]

I've never found it hard to tell when things are loading up. You hear the ropes creak in the sheet winches. Winch loads get much higher. The boat does heel, maybe not 35 degrees, but it does heel, and you can feel it. Then there's the boatspeed.

[bill good]

Winds forecast 30Kts gust to 40Kts reef for 30Kts. Cats don't lean over to spill the wind like 1/2 boats. They just go faster!!

[2Wind]

Above - all good comments.

Here are my set of "Rules". I'm sure others have their own....

Up wind, above 18-20kts, leeway, rig loading, sheet/winch load, ride, heal and comfort are all compromised without taking a reef. In doing so, you will suffer no significant change in boat speed with improved VMG. Rule 1: Reef upwind by 20 kts., be preparing to reef at 18 kts. (When upwind use apparent wind speed)


On a reach: Loads will be less but apparent wind will be higher. The boat may well approach hull speed so the likelihood of any significant gain from having more canvas becomes moot. Generally, I'll again be looking to reef at 20 kts. perhaps with gusts to 25-26, always being mindful of not being caught out by abrupt increases in wind speed. You can always bear off and drop apparent wind, but sooner or later you have to come up to put in the reef. Rule 2. On a reach, reef near 20 kts. apparent, perhaps a few knots higher is the sea state is kind.

Down wind: This is where I've been caught out in the past. You must watch true wind speed as your apparent will be deceptively low. Certainly if you start to surf repeatedly, reef. I would generally be well reefed with a true wind of 20 kts. unless well crewed with a kind sea state where speed was key. Rule 3: Down wind reef at 20 kts. of true wind.

The reality is the hulls of boats like my Lagoon are very buoyant in the bows, and the rig is very strong, so being caught out with say 30 kts. and a full main has never been a real problem, but one tries not to rely on safety margins. Generally reefing will make the ride more comfortable, bring a genuine sense of confidence and reassurance and in a non surfing hull, your boat speed and VMG will not suffer. Rule 4: Reef early, not late.