Spinnaker set up
Ya, no pole for an asymmetrical spinnaker, but for sure for a symmetrical spinnaker. I will go over each. By the way, in 1978 I purchased a new Seidelmann 25 (long gone now) and so know your boat too.
The symmetrical spinnaker (like a tri-radial, etc.) needs a topping lift, a foreguy a spinnaker halyard and two spinnaker sheets. I recommend the foreguy block be installed on the foredeck either right in front of the hatch or right behind it. The topping lift can be made internal by cutting a hole in your mast to accommodate a Harken exit box and then you can route it out of the side of the mast with a Schaeffer exit plate (4' off the deck or so) down to a block on a spring or a halyard lift block to run it outboard to a cheek block to bring it aft to the cockpit. Lead it to a Harken 150 cam cleat or a Ronstan cam cleat. The Foreguy should run aft to the cockpit on the same side so that the topping lift and the foreguy can be operated together to raise or lower the pole.
The halyard should be run to the opposite side, but the same way, but only I would run it to a clutch in front of the secondary cabintop winch so the winch can be used for other jobs (you cleat it off in front of the winch and then take the line off so you can use those winches for your spinnaker sheets. The masthead can be fitted with a bale so you can attach a spinnaker halyard block to it. Run the halyard through this block and route it aft the same way you did the topping lift. BTW, you don't have to go internal with the topping lift if you don't want.
I would use 3/8" line for the halyard and sheets. You can use 5/16" for the topping lift and foreguy.
The halyard should have a snap shackle on the sail end.
The spinnaker sheets should have snap shackles with big bales on them (to keep them from getting stuck in the spinnaker jaws).
The topping lift and foreguy should have Wichard 2481 snap hooks. These are fast to do and undo on the spinnaker SS ring on each pole bridle.
All should be eye spliced.
If you want to get fancy, then add a port and starboard twing line. Use the same Wichard hooks and route them from midships to the cockpit. You can attach small blocks (use 1/4" line) to the slotted aluminum to rails, bring the twing aft to another small block (like a Harken bullet block) adjacent to the bulkhead (companionway) at the leading edge of the cockpit and then route them over the genoa track to a camcleat with a fairlead (to keep the end of the line near the cleat).
The twing is attached to the after guy side, or both sides if you are in very heavy air.
The two sheets take on different names during use. The one attached to the pole is the after guy and the opposite is the sheet. When you gybe the pole, to the other side, then that line becomes the after guy (on the new side) while the other becomes the sheet.
You run these two lines to 3" blocks attached to the slotted aluminum toe rail at the aft corners of the boat. They then route to the secondary cabin top winches which you should mount on either side of the companionway sliding hatch (if they are not already there).
The pole should be the "J" area of the boat. That is the dimension from the leading edge of the mast to where the forestay attaches (stemhead fitting). That is the longest allowable length for PHRF handicapping. If you ever race, your pole could be measured. It will have a bridle on top and on the bottom for the topping lift and foreguy (often called downhaul) attaches. The pole attaches to a track on the mast. I recommend 4' of Schaefer 1"x1/8" track with a spinnaker car slide. The investment casted one is much stronger than the one with a welded on ring. There are other manufacturers of similar track, like Ronstan. Which ever is more available and affordable to you.
Basic spinnaker trimming is such:
Keep pole square with the apparent wind, keep it perpendicular to the water in most cases and keep the corners of the sail on the same plane (not one higher than the other).
When the pole is square with the wind (ease or pull in the after guy to find this position), ease off the sheet until the leading edge of the sail begins to curl. Keep it from curling, but always keep it on the edge. If your course changes or the wind changes, you keep squaring the pole to suit and then trim to suit.
You raise and lower the outboard end of the pole with the topping lift and foreguy. If the outboard end is pointing up, you then can raise the inboard pole end with the car on the slide to keep the pole perpendicular with the water. This keeps the pole end pushed out the farthest too.
When you gybe the pole, your foredeck ape takes the pole off of the mast and hooks it to the free corner of the spinnaker. Now you have the pole attached to both corners of the spinnaker. As the helmsman slowly turns the boat so the wind passes across the stern, you release the pole from the sail on the leeward side and attach that pole end to the mast. Who ever is operating the topping lift and foreguy probably will have to ease the foreguy to allow the foredeck guy to move the pole around freeley. Otherwise it might prevent him from pushing the pole outboard enough so that he can attach the pole on the mast.
There's a lot more to know for fine tuning, but that is the basics.
Now asymmetrical spinnaker set up.
You don't need a pole or anything on the mast like a track or eye. You do need a halyard and you need two sheets and you need a downhaul.
The downhaul goes through a block attached near the stem head fitting and then it leads aft to the cockpit where it can be adjusted. It is attached to the tack of the sail.
The sheets attach to the corner of the spinnaker (clew).
The halyard is attached to the mast just like the other spinnaker and then should lead aft to the cockpit for constant adjustment. On the other spinnaker, you pull the halyard all the way to the top and leave it there. With an asymmetrical spinnaker you can adjust it in and out.
If you don't have roller furling, you should attach a snap shackle to the tack of the A spinnaker. This attaches to the forestay and slides up and down as you ease or pull in the down haul.
If you have roller furling, the furled sail will prevent you using that snap shackle, so you then should buy an ATN Tacker which is a big white yoke which will slide up and down the furled genoa on the forestay. The tack of the sail attaches to it as does the down haul. You can make one with wooden beads that roll around some rigging wire in a loop configuration. The wire then has two Nicro Pressed eyes on the ends and the loop is large enough to go around the furled sail. The two loops attach to each other with a shackle and at that point it attaches to the tack of the sail as well as the downhaul.
You basically gybe the sail and trim it like a genoa, but you are gybing around the front of the forestay instead of inside the foretriangle.
You can carry an A chute closer to the wind (windward even), but not so a poled spinnaker. Usually a beam reach (90 degrees to keel line) is the most you can carry a poled spinnaker (a little higher sometimes), but much higher on a A chute. With the pole type, the pole will be against the forestay at a beam reach, but is is wide to pull it aft just enough so it doesn't touch. Keep it off the forestay.
With the A kite, sailing closer to the wind, you want to pull in the halyard and pull down on the down haul so the leading edge (luff) of the sail is stretched out more like a genoa. As you fall off on the wind, you can ease the halyard and downhaul so that the sail bellies out more, opening up the luff. You ease the sheet as you fall off the wind and pull it in as you sail more close hauled.
Well, that is the Spinnaker 101 course of the day. Hope it helps.
