How much do you need a mainsail downhaul?

[Quantico Frank]

I haven't at least actively sailed in all that many different sailboats, and the ones I've actually actively sailed in have ranged from small (my P165?) to super-duper small (Sunfish.) There's a downhaul and cleat on my P165, but I've never encountered forces that I can recall that actually push the boom upward in the mast track. What am I missing, or have yet to encounter? Thanks!

[Wolverine]

If the main sail has slugs or cars, the boom can rise when a strong wind fills the sail. A bolt rope helps to keep the bloom down, however it still can be lifted.
It also important to keep the correct sail shape.

[eaglecreeksailor22]

On my Catalina 25 I would set on the edge of the boom to tension the luff instead of useing a cunningham.

[Brian N.]

On the P165, which has "end boom sheeting", I use the boom vang to help keep the boom down on a broad reach and run. This helps take some of the "belly" out of the main near the foot and importantly, to keep the boom from rising since the main sheet is relatively slack. Not critical when just lazy sailing, but if you're looking for the best performance, the vang is useful. The downhaul cleat just anchors the main at the luff, and is not really used to substitute for a cunningham. On the Ensign, the cunningham was a useful adjustment for sail shape, especially at the luff of the main. Hope this helps

[Quantico Frank]

Yeah, I use the boom vang all the time and of course end boom sheeting. I've dutifully tied off the downhaul to its cleat so far—- unless I forget it, which happens, but last season first the cleat broke, and now there's an issue with the piece that goes into the slot of the mast that the cleat screws into, and I'm just wondering should I care. Anyway, thanks!

[Riggerdood]

On the DS, I always used the boom downhaul in conjunction with the halyard to maintain proper luff tension. The RS22 has a fixed gooseneck, so I use a cunningham in conjuction with the halyard to achieve same.

[Quantico Frank]

Got it, makes sense, Tim! I'll leave it on my list of things to fix.

[Riggerdood]

What's going on with the mast slot cleat tube Frank?

[tjspiel]

On the DS, I always used the boom downhaul in conjunction with the halyard to maintain proper luff tension. The RS22 has a fixed gooseneck, so I use a cunningham in conjuction with the halyard to achieve same.

That's my understanding of the distinction. I guess there are some class racing regulations where the head of the sail and the foot of the sail can't go above or below certain positions and in that case you have to use a Cunningham to set luff tension.

I'm pretty conscious of what I'm doing with the downhaul Frank but usually don't mess with it much while I'm sailing unless conditions change a lot or I set it wrong in the first place.

[Quantico Frank]

What's going on with the mast slot cleat tube Frank?

It's cracked, so I'll need to replace it, as I recall, although I haven't laid eyes on my boat since October. Hopefully this week, since I literally just finished splitting up the wood from my downed tree yesterday after weeks of work, and now can turn my attention to non-"emergencies" like getting the boat ready for the season. 

[Riggerdood]

That's my understanding of the distinction. I guess there are some class racing regulations where the head of the sail and the foot of the sail can't go above or below certain positions and in that case you have to use a Cunningham to set luff tension.

The DS class association definitely had those bands in the measurement rules Tom. Luckily, I never raced in any regattas that required measurement, and I doubt my boat or sails would have passed anyway. 

[Riggerdood]

What's going on with the mast slot cleat tube Frank?

It's cracked, so I'll need to replace it, as I recall, although I haven't laid eyes on my boat since October. Hopefully this week, since I literally just finished splitting up the wood from my downed tree yesterday after weeks of work, and now can turn my attention to non-"emergencies" like getting the boat ready for the season. 

Well, luckily the tube and cleat are fairly standard parts, and should be fairly easy to source, maybe directly from Bill?