Icicle Series 2018

[STuma]

Well, it is that time of year where some extend their racing season in the colder months to enjoy hot beverages and food afterwards - GBCA Icicle Series.

You can find the Sailing Instructions at the following: https://gbca.org/resources/Documents/2018%20Icicle%20Series%20Sailing%20Instructions.pdf

The only change this year is the addition of the MulFoi class. "• MulFoi class – Any boat that can plane or foil. This is an experimental class to include multihull, foiling, and/or planning boats. The intent is to remove high performance boats from Club Handicap into a class with a similarly relaxed handicapping process. Before a boat can be entered into this class, it must complete the entire course once. This handicap will be assigned and modified each race by GBCA, similar in style to Club Handicap. The new class will be scored independently of the other classes for the Series Results and all prior finishes will be moved to the new class. This will affect the current results for other classes."

Schedule:

#1     January 6      Standard

#2     January 13    Reverse

#3     January 20    Standard

#4     January 27    Reverse

#5     February 17   Standard

[Funk]

Define planing boats?

[shawn]

A displacement hull can only go as fast as hull speed of the boat.  A planning hull can go faster then the displacement boat because it sits on top of the water with less wetted surface.  A foil gets the boat out of the water altogether and goes faster than a planning boat. That is not an officail answer just my version.

[Hamburger No 1]

Shawn - you described well what planing is. But the question is what distinguishes a planing from a non-planing hull. Ok, so generally a planing hull is relatively flat and the boat is relatively light. But different boats plane at different wind speeds. So, I think the question is perfectly valid: when is a boat considered a 'planing' boat? I've had the J/109 on a plane. It was scary as heck and I still want to claim that the boat isn't a planing boat. Let's get an answer from all our naval architects!

[shawn]

found this on a boat builder forum
describes it pretty well with math and everything....Maybe it will clear it up or just muddy the wafter more?

Displacement hulls are designed to travel in the water at a typical hull speed of 1.34 *(square-root LWL) in knots. This formula applies to the distance between bow and stern wave crests. At faster speeds, wave making resistance increases exponentially because the vessel is trying to climb on top of the bow wave - meanwhile the stern is being sucked down by the dynamic forces from the "hole" created in the water as the vessel moves forward. Displacement hulls tend to have pointed bows and sterns because this form poses the least wave making resistance at "displacement" speeds. It takes a relatively small amount of power to push a displacement hull at its "hull speed."

Semi-displacement hulls tend to have wide, flat aft sections - like a New England lobster boat. These hulls are designed to partially climb on top of the bow wave and separate the transom from the stern wave. Semi-displacement speeds are usually in the area of 1.5 to 2.5 *(square-root LWL) in knots. It takes a *lot* of power to drive a hull in the semi-displacement speed range. The flat wide stern sections help to provide additional lift in the stern to partially overcome this problem.

Planing hulls are designed with straight sections aft. A typical deep-V bottom hull has the same angle to the 'V' (the same "deadrise" angle) from midship to transom. They are designed to climb completely out of the water at high speed and "hydroplane" on top of the water. At planing speeds, water is breaking cleanly from the transom and the hull is riding on its straight aft sections. The greatest resistance at planing speeds is frictional resistance. It takes more power to climb out of the water over the bow wave than it does to maintain planing speed once this is achieved. At very high planing speeds (>25kts) any change in deadrise angle in the aft sections of the hull can adversely affect performance. Hulls with a "variable deadrise" angle in the aft sections (where the angle of the 'V' decreases and flattens toward the transom) are a further modification of the semi-displacement hull form. They are more easily driven at speeds < 25kts, but at higher speeds tend to push the bow down due to the higher dynamic lift in the aft sections. Variable deadrise hulls can actually become unsafe at very high speeds >30kts because of this tendency - it is possible for the bow to dig in and cause the boat to broach at high speed.

[Hamburger No 1]

Ok, thanks! So: who decides if a boat is semi-planing or planing for the purpose of class assignments?

[shawn]

we are trying to figure that out because we can only do hull speed 8-9 knots and other boats can do double digits for the whole leg how can that work out in a handicap? Scott is saying in his post we need to provide enough boats to nake the classes so he can split them.  C&C race together J's race together, and so on.  So I thought the level 120 would do that but it looks like we need to be more specific.  Displacement class? and non displacement? just stirring.

[Terry Young]

Foils! That's the trick! I have an idea how to install foils on FireWater, I wonder it Walter would get upset if I were some two foot long gated holes in his boat? I bet that would make us go faster once we baled all the water out of the boat!

[shawn]

Terry
I fixed the steering before I left hows the foils doing?

[STuma]

we are trying to figure that out because we can only do hull speed 8-9 knots and other boats can do double digits for the whole leg how can that work out in a handicap? Scott is saying in his post we need to provide enough boats to nake the classes so he can split them.  C&C race together J's race together, and so on.  So I thought the level 120 would do that but it looks like we need to be more specific.  Displacement class? and non displacement? just stirring.

According to the party scuttlebutt, I've heard that about 80% of the fleet has done 15+ knots at some point in life... A displacement hull will not get anywhere close to that. From my experiences, a displacement hull will hit it's "speed limit" (square root of waterline times it's drag coefficient) and just start to sink from the bow and stern waves collapsing on top of the boat. The boat digs a hole in the water and jumps in it. Anyone who has sailed an IOR boat can verify that.

I have had some one-on-one discussions about this 120 class. I have not been told their reasoning on why to split of disp vs non-disp. I can make an assumption, and get it; but we don't have the numbers for dividing classes even further. Boats perform differently in different weather conditions. This makes a fantastic argument for ORC Club. Tell me the class of boats, the wind and the course; and I will tell you who should win before we leave the dock. That is handicap racing. Just like I don't want to race against the C&C's in <12 knots of breeze on the J-80, they don't want to race against me in 20+. But, luckily, most of our wind is between 10-17 knots on GB.

[shawn]

Icycle series Erie Pa.
Attached photo

[Terry Young]

Scott, any possibility of posting photos of the GBCA leader, so that the new members and old members with bad memory will know who they are and what they look like, so if they have a question know who to ask. They do this in other clubs and it is helpful to new and old members. Just my thought, and looking forward to another year of sailing with my GBCA friends. Terry

[STuma]

Scott, any possibility of posting photos of the GBCA leader, so that the new members and old members with bad memory will know who they are and what they look like, so if they have a question know who to ask. They do this in other clubs and it is helpful to new and old members. Just my thought, and looking forward to another year of sailing with my GBCA friends. Terry

Are you asking about the board members? They do have shirts with name and position that I have seen previous board members wearing during the social events. Or, pictures with their bio?

But, very good idea.

[pete]

Have the results been posted for race 1 ? if so where ?