end boom versus mid-boom sheeting on Sun Cats

[Les]

On older Sun Cat's they used mid-boom sheeting with a traveler on the bridgedeck, looks like around 2008 they went to end boom sheeting.

I have looked at many photos under sail (especially with bimini's) and I think the mid-boom provides better sail shape but makes it harder to get in and out of the cabin.

Would love to hear what you Catty sailors have to say about both methods.

[cavie]

I much prefer the midboom sheeting as it moves the Bimini back towards the rear of the cockpit. This leaves a nice gap betwen the bimini and the cabin. Very usefull in boarding at the dock and moving forward from the cockpit to the deck. A simple flip of the wrist moves the mainsheeting out of the way. Remember, this is not a race boat, moving the mainsheet to the low side, will not loose you a place at the finishline. the curve at the stern is the best seat in the house. Midboom sheeting places the bimini over the best seat in the house. One line line fits the Suncat way of thinking better than two.

[capt_nemo]

On the other hand, I much prefer my end boom sheeting. If Bimini position (and use) is NOT A PRIMARY CONSIDERATION for main sheet position, end boom sheeting provides adequate sail shape under most conditions (More later). It gets the mainsheet and traveler out of the way of the  companionway for easy access to the cabin, removes the traveler track and mainsheet tackle from the bridgedeck so a cockpit filler cushion can be fitted (great for extra width required at shoulders when lying down on either cockpit seat cushion), moves the double ended maisheet close at hand to the "best seat in the house", as cavie points out, whether you're steering from the high or low side. This close at hand location is important to me since I tend to adjust my mainsheet more frequently than others while keeping an eye on the behavior of several sets of windward and leward tell tales slightly aft of the main'sl luff and even aft of the gaff.   I'm one who deploys a Bimini only when needed so it's not in the way as often as it might be for others.  Another SunCat Owner WITH BIMINI AND END BOOM SHEETING recently mentioned to me that he was considering making the sliding tracks for his Bimini longer forward so that the Bimini could be moved FORWARD to provide shade, better airflow and rain protection below with the companionway hatch in the forward position. With regard to sail shape, the downward pull on the boom, as exerted on mid boom sheeted boats, can be achieved if desired by using a boomvang tackle. This tackle would be attached to the SAME under boom fitting used on mid boom boats which was left on the booms after the switch to end boom sheeting. Yep, it's still there! The other end would be attached to midship cleats mounted either side of the boat. Thus mounted it not only serves to adjust sail shape on reaches but performs the double duty as a "Preventer" when sailing downwind, especially "By the Lee".

[Tom Ray]

Well, we all learned at the Sun Cat Nationals that the blue ones with mid-boom sheeting are fastest.

Seriously, mine came with mid-boom and I do not want to change it.

End-boom necessarily means more feet of mainsheet, and I think shorter is better when it comes to lines.

My boom rises and needs a vang anyway, and in lighter winds I can imagine that all that extra line hanging out there might actually do some good in keeping it down. Either way you go, the boat needs a vang if you really care about speed downwind.

The traveler can be moved to the side and is not really in my way going in and out of the cabin so much as it's just generally interfering with passengers (and dogs) lounging around. OTOH, if I had end boom sheeting, I would probably have a dog on half the sheet most of the time.

I have the factory cockpit cushions, which are very nice. There is a cutout for the traveler. They did not quite cut out enough. The cushion goes right up to the traveler track, and binds a bit on the traveler car itself, especially off the wind. It's a minor annoyance. Maybe one day I'll have the cushion guy I know fix it, probably not.

Our bimini is on tracks and a pretty wide range of positions are available. The sun still manages to get somebody. I am going to make roll-up mesh side curtains all the way around. I have them on my porch and on my Sun Cat shelter, and they're great.

I have considered end-boom sheeting for a couple of the reasons Capt. Nemo mentioned, and would add that in strong winds with the full sail, there is a LOT of force required to sheet in with the mid-boom sheeting. I have to either use two hands or head upwind a bit until the sail luffs to sheet in with one hand. Pulling from the end of a lever is easier than pulling from the middle. OTOH, I can move my boom faster than a person with end-boom sheeting who is pulling the same number of feet of line.

Lots of tradeoffs, but either way they are lots of fun!

Sun Cats Rock

[Shawn]

"End-boom necessarily means more feet of mainsheet, and I think shorter is better when it comes to lines."

Move from end boom to mid-boom and you cut your lever length in half. If you want to keep the effort the same as before you would need to increase your pulley ratio which then adds back some line.

Shawn

[Tom Ray]

Problem is, they didn't! Mid boom ones have 3 legs of mainsheet on each side of the boom, for a total of 6. I have 4 legs under the boom. As I said, it does make it a bit hard to pull in strong winds. I did not mention it, but that also means you might have to pull really hard with both hands to release it if the need should suddenly arise....

[Joseph]

Just to add on this issue my own tiny speck of sand:  when I ordered "Sassy" I had the option of either end-boom or mid-boom mainsheet. I preferred the end-boom design mainly because of having the block-cleat for the mainsheet at closer reach for when the time comes to let it go. A traveller is not really needed in the SunCat (well, maybe now that there are "Nationals", and soon possibly "Worlds", this should be reconsidered). But I did also insist on a "soft" boom-vang (i.e., not a rigid one) with purchases, attached at mid-boom and aft of the foot of the mast. The floating goose neck is not an issue since when sailing the goose neck is always fixed by the tension developed between the halyard and the downhaul. this kind of boom-vang is superb in keeping the boom down and flattening the sail while maintaining sail twist when sailing broad-reach or running in stronger winds. Yes, in that position it does not act as a preventer (something that might not be a bad idea to have, since the lack of a jib deprives the skipper from advanced warning for an accidental gybe - which may also be a good reason for hoisting a small jib) but on the other hand it does not affect the sail angle set by the mainsheet.

Although easily solvable, having the mainsheet attached to the end of the boom has also some glitches of its own: The bimini needs to be moved forward when down as otherwise it rubs against the purchases of the mainsheet, and when the mainsheet is not under tension the blocks tend to rub against the gelcoat. Replacing the springs at the blocks with the larger kind significantly improves this condition. When gybing, if the mainsheet is not collected to the centre before gybing-ho (as it should!) it can (and it will - remember Murphy!) snag with the outboard or anything else it may find on its way.

PS.- While Sassy happily hibernates inside a barn, I have been cheating on her in the Southern Seas with a Wharram Tiki 8m (http://wharram.com/tiki8intro.htm) but I long to be back to her in the Spring and return to the inland waters of the Great White North.

Joseph.

[capt_nemo]

Ditto on strong springs under the mainsheet blocks to keep them from banging against gelcoat when not under tension. You were lucky, you had springs to begin with - my brand new SunCat was delivered
rigged without them. Adding springs was one of the very first obvious mods I made. Ditto also on controlling the mass of spaghetti mainsheet when gybing with double ended end boom sheeting. In light air I
use two hands to carefully gather and control the mainsheet, making darn sure that it's not going to get caught on anything, before safely flipping the entire mainsheet and boom over to the opposite side. In
moderate to heavy winds, bringing the boom in to the centerline with mainsheet before crossing over is definitely the safer way to go with far less shock on the entire rig.

[gray]

Fascinating discussion. I am happy with my mid boom arrangement on sv Nemo (Capt Nemo take note - you are welcome aboard anytime and Lake Champlain is a beautiful place to sail).
I never thought I would need a bimini up here at these latitudes but last summer was a scorcher and I had to use a golf umbrella on occasion (much easier going downwind!). So I am considering getting a bimini and would appreciate any recommendations. I think I also need to follow up on Tom's suggestion of a boom vang - how does it act a a preventer though?

[Tom Ray]

Gray, Captain Nemo attaches his boom vang to a midship cleat on each side, and changes it on each gybe (or something, correct me if I'm wrong, Don).

I don't really care for preventers in any but the lightest air. The helmsman is the preventer, and if he fails, the strains on backup preventers can be huge.

I'm planning on putting a vang down to the mast in the conventional way. If I wanted to use it as a preventer, I suppose I could clip it to a shroud or something.

[capt_nemo]

I don't have a boom vang/preventer mounted yet. But yes, if the standard installed boom vang is equipped with quick release snap shakles you would release the end at the base of the mast and attach it to a midship cleat thus using it as a preventer. I installed midship cleats on my boat for a number of reasons, an anchor for a boom vang used as a preventer being one of them. And, you would have to release it and change to the other side with each gybe. My midship cleats are near to the cockpit so accomplishing this would not be difficult. Besides, I rather like the more vertical downward pull of the vang as preventer, like that of the mid boom sheeted boats, for beam and broad reaches as well as runs. I would probably only rig the vang as preventer when sailing in heavy winds or for long periods on reaches and runs. The standard vang attachment between boom and base of mast is probably needed for close and very close reaches to aid in controlling sail shape. (Note I did not use the term "close hauled" 'cause we Cat sailors don't ever bring our booms in close to the centerline.)

[gray]

Thanks for the information from Tom and Cap't Nemo on vangs.
Any advice on biminis - what kind to get , mounting option - is that hard, can you still see the sails?

[Tom Ray]

I have the factory Bimini. It's not hard to install, just a couple of tracks and padeyes. You can slide it fore and aft a bit, depending on where your mainsheet is and where the sun is. You can't see the sail because it's up there where the sun is!

[patfurr]

Les,
I am learning some interesting little quirks with the end of boom sheeting.  Yes, try to keep the port and starboard sheets relatively close in length. This is easily done once you have settled into the new tack.  For gybing, there is just way too much sheet to strip in to control the boom by pulling through traditionally.  I just grab up the entire windward bundle in my aft hand as far up toward the boom as I can, and pull that whole glop of sheet in as I gybe and just let it slide out without over-gripping it once the boom has passed across.  Don't try too hard to slow it down as that may end up with some rope burn.  It isn't elegant but it keeps things settled down.  And finally, beware of too much sheet out on the big tacks as sometimes the sheet tends to foul in the aft cleats or worse yet the boom gallows.