Eruttan,

  Some thoughts, which others are free to correct.

How does one open the hole to a size that one can fit the patch through, while it is under water? Hand saw? Does this get complicated with kevlar?

  The patch would be the same width as the diameter of the hole, but longer.  You could also put a cross-piece inside and wire the two together.  You'd still want to seal it with some sort of underwater-curing urethane or epoxy.  Or you could "dive" under the boat's 1' draft and put a larger patch on.  The flat surface would be most useful in this regard.

  And of course, you already have a hole saw set on board that fits to an extension on your cordless drill, right?

  Or you get outside the boat.

How likely is it that a hole breaches the hull, given the crush bows?

  Unlikely.  But you could do it if a wave lifts the bows over a rock and then it contacts the hull in a trough.  It's probably most likely to happen inf you're bouncing up and down on rocks while beaching  Or you could potentially have debris, a boat, or a dock/pier break through the submerged vertical section.

Drying out on a deep V is good on sand, but just as likely to end in damage on rocks as a flat bottom. Both need a couple of tyres or planks to sit on.

The damage, if any, would be the same for either hull shape, right?  I imagine the lighter/longer boat would have the advantage, as less force per area?

  Unless you have a beautiful, flat, sandy shoreline, and are beaching the boat in very light surf, any hull shape can easily get damaged.  Longer/lighter has the advantage in terms of weight, but a disadvantage in terms of surface irregularities the hull is likely to encounter.

  In any case, unless the situations are ideal, I'd still want tires and maybe some planks for the boat to sit on.  There's always something that's going to want to gouge the hull; perhaps some beautiful shells, and it's a rare beach that wouldn't have any random rocks. 

  What people rarely talk about is the cost of bottom paint.  I'm a frugal and efficient man, so the idea of scraping off a few hundred dollars of bottom paint, and/or having to repair it, just doesn't work for me if the scraping can be avoided.  Even if I had a ten-year hard coating solution like CopperCoat, I'd still want to baby that hull as much as possible.

  It's for this reason I got a trailer for our dinghy (which weighs 300 lbs with a motor on it).  I used to carry it down the granite shoreline with three neighbors/friends, but inevitably they'd get lazy and start dragging it across the rocks.  When I'd object, they'd deride me for wanting a pretty bottom that was going to be underwater all summer anyway.  But they weren't the ones who were going to have to get under the boat and remove the growth, or try to repair the actual gouges.

  Lift the boat up a few inches on some sort of padded bunk.  The tires can cushion the impact, make up for surface irregularities, protect the hull surface, and let you get at more of the hull than if it were resting on the beach.

The shallower the hull, the easier these are to put in place.

Why is a shallow hull easier? Shorter jack?

  The boat is still floating when you put these in place.  Trying to get beaching bunks/tires situated on a deeper V-profile is going to be more problematic than a shallower flat profile.  But both are going to be easier than a monohull with several feet more draft.

  I think you might have to get wet with both unless the water is very calm.  That said, you can put a tire right up against a flat bottom, tie it in place, and it will stay, and will also distribute weight/impact over a large area.  You'd need a long hull-shaped bunk with flats on either side of the V in order to get the same cushioning and force distribution with that profile.

Do removable tanks matter?

  Someday your tank will get fouled with bacteria, contaminants, or sediment.  And/or degrade to where it's leaking its contents out or allowing other things in.  I suppose a welded titanium tank will never corrode, even if starved of oxygen, but you'd still have the other issues. 

  Having a tank you can remove and/or replace with a new one is very handy.

Does one have to goto the mast to hook the luff downhaul to the reef point?

 
  Some boats have two or three lines running to luff cringles to make reefing quicker.  Those with single-line reefing have a single line that goes to the luff on one side and the leech on the other, running through some blocks, that you can secure with a single cleat or clutch.

  That said, an ultra-simple rig with dyneema hoops and a wishbone boom would probably work better without trying to get fancy with a single line.

  The key is that the boat is in neutral, the sail is in neutral, and you're in a protected cockpit area (not up on an exposed bow). 

  Compare that to the worst case in a unidrectional boat with a stayed rig:

    - You're headed towards an object and need to tack before reefing because you can't just stop.
    - The mainsail is pinned against the shrouds and won't come down.
    - The headsail sheet got jammed in the furler and you can't furl it or get it to switch sides.
    - Rough seas.
    - Big wind.
    - You're alone and can't steer the boat while also going up to the bow.
    - Or you're injured and you're talking your nephew through what to do.
    - Again, while headed towards that shoal.

  It's unlikely that everything would happen at once, but it's easy to imagine a few of those things happening at the same time.  They have for me.

  Heck, one day I watched a ferry pilot pinch a boat between the ferry and an island in 25-knot wind when the sailboat was running and the mainsail was pinned on the shrouds.  That poor guy had no options.  Thankfully the ferry gave him some room at the last moment, but if he hadn't, the sailboat was going to be in a world of hurt.

  A bidirectional boat with an unstayed rig, however, could just stop and reef whenever needed, and without putting any crew in harm's way as waves pound the working area up by the headsail.
 

Is it reasonable for me to suggest that a slow boat is less safe?

  It's a wash.  Speedier is safer in that you have more options in how to get to safety or how to get past the edge of a squall.  Unless you push it too far with that supersized rig and then end up having a really bad day.

  It's like knives.  A sharp knife is safer if you're careful and know how to use it.  It will cut with less force, is less likely to fly off uncontrollably (because you're using less force), and will cut more quickly (and sometimes time is of the essence).  Unless you lose your focus, in which case a butter knife is safer.  I've seen more than one person get cut by an ultra-sharp blade because they weren't paying attention.

When you have a moment, would you explain where you are with the bidirectional blades and the one way blades?  I imagine the one way blades give more performance per wetted area, and the Steinar's speed demon might be the impetus for its renewed development.  I imagine the bidirectional are simpler to sail?

  Unidirectional foils will be more efficient.  But you'll have to rotate them 180 degrees each shunt.

  Bidirectional foils will be less efficient, but you can configure them to give a touch of lift to windward, and they only have to turn a few degrees.

  Personally, I'm willing to give up a bit of performance for convenience.  Plus the bidirectionals are almost made for tillers.  I love tillers and really don't want to deal with a wheel.

  (Though I have to say the tilting wheel on the 50 and 60 that can be in the cabin or out on the deck is brilliant).


        - Mike

 

I have questions

| Flat panels, you poke a rectangular piece of ply through the hole, rotate it and let water pressure hold it in place.

How does one open the hole to a size that one can fit the patch through, while it is under water? Hand saw? Does this get complicated with kevlar?

If you holed the ww hull, how many inches would one expect the hull to sink?
Has to be different per boat, and according to it's loading, but is this a calculation that is known?
Can you step through how you would imagine a hull hole would be repaired at sea?

How likely is it that a hole breaches the hull, given the crush biws?

| Drying out on a deep V is good on sand, but just as likely to end in damage on rocks as a flat bottom. Both need a couple of tyres or planks to sit on.

The damage, if any, would be the same for either hull shape, right?
I imagine the lighter/longer boat would have the advantage, as less force per area?

| The shallower the hull, the easier these are to put in place.

Why is a shallow hull easier? Shorter jack?

| Peter said it all about bilges for stowage. Tanks that can't be easily drained and cleaned are useless if you are sailing off the beaten track.

Does removable tanks matter?

| On a harry (or any unstayed rig), dump the sheet, the rig weathercocks and the boat drifts. Trip the main halyard lock and the head falls to the next lock down. Unhook the luff downhaul, hook it on to the reef point and pull it down. Pull in the leech reef line. Sheet on and go.

Does one have to goto the mast to hook the luff downhaul to the reef point?

| The sail area comparison was in response to Owly's performance comments. If he is happy with 30' cat performance, he could actually have a smaller rig on the 40' harry. Or, the hp rig could be bigger for the same safety margin and performance would go up accordingly. As would cost.

Of course, I see that now. Without regard to Owly's desires, I have considered safe speediness of a boat as a positive safety issue. Is it reasonable for me to suggest that a slow boat is less safe? Again, not much of a sailor here...

| You are correct about rudder developments. Already seeing things that can be made simpler, particularly with the one way blades.

When you have a moment, would you explain where you are with the bidirectional blades and the one way blades?
I imagine the one way blades give more performance per wetted area, and the Steinar's speed demon might be the impetus for its renewed development.
I imagine the bidirectional are simpler to sail?

I love how you don't get biased against ideas. Develop them all simultaneously!

| I am no keener on sitting in the sun or rain than you guys. But I do enjoy sailing (ie seeing the sails), sun rise, sun set and the sky at night. Any shade should be removable quickly and easily.

We had spoken on dodgers previously. I still have not seen a design that would lend itself to the modern HP cockpit.

| The cabin on the EX 40 is 1.5m/5' wide x 4.8m/16' long, and has direct access into the hull, which is another 750/30" wide.

That seems a big cabin.
But I thought Owly was doing a bridge deck cat?

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Posted by: Mike Crawford <mcrawf@nuomo.com>

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