I try to read forum posts to keep a pulse on customer experience but rarely make comments. Since "the buck stops on my desk" for several of the topics being discussed, I thought I should jump in and explain the reasoning behind the choices. It is always a tough thing to design "break-here" points into a system but in some cases it is necessary.
For example, on the Island aka bars, where the diagonal cross brace attaches, without the plastic fuse (nylon screw), the bars will fold and break at the weld location in the event of a ama collision which would be a disabling and expensive failure. I tried all diameters and material types for this shear pin until I arrived at the current size which will always fail before breaking the bar. Even un-threaded pins will occasionally result in a broken aka bar. It is very difficult to break this pin during sailing conditions although I have heard of a few Hawaiian Island users breaking them on their extreme island channel crossings. Their solution is to back-up the diagonal bars with diagonal tension lines to secure the ama's out.
Rudder pins are another such design situation. The goal is to provide a system that will not fail under sailing condition but will fail and protect the boat in the event of extreme loading. The worst case scenario for any sailboat rudder, (catamaran, skiff, dingy or Island) is backing down on the rudder in the surf. Since rudders don't kick-up in reverse, tremendous rudder loads are generated with a fully-loaded boat being lifted and thrown back onto rudders hitting the beach. Common failures on Hobie Catamarans are either broken rudder blades, aluminum rudder castings or quite often torn-out gudgeons from the transoms leaving a massive hole in the hull. Many users have used aluminum or nylon rudder pins to prevent this. With the original over-sized Island Twist-and-Stow rudder, the rudder housing would break in half before the pin broke, as I experienced on my second EC while trying to depart in my TI through some sizable surf at Stump pass. Fortunately, I had brought spare rudder assembly and was able to salvage the trip. With the new Island Sail Rudder, without a breakable rudder pin, the backwards surf collision could break the gudgeon and possible the rudder, but most likely it will rip the brass inserts from the plastic in the transom. There is just no practical way to design the rudder, gudgeon and stern inserts to handle the massive loads generated by this use case. I understand the predicament that designing for this unique use case creates first hand as three years ago I had had a pin shear on my V1 AI in the middle of a very rough Sarasota Bay. It turns out this pin had survived 2 previous EC's as well as a large portion of a UFC and was likely fatigued. Now, I always start an EC with a fresh pin and will even put a fresh one in prior to starting a particularly difficult crossing (Florida Bay this year). Sure, I could put a steel pin in and not worry about having a failure during a crossing, but I wouldn't want to risk the chance of completely disabling my boat and leaving me stranded with torn-out gudgeon inserts or a busted rudder. Much of design is about managing trade-offs and the sacrificial pin to prevent game-ending failures has in most cases proven to be a good one. I think there is a good chance pins are getting fatigue loading during trailering. To prevent this, the rudder could be removed and stowed on deck so that the pin isn't holding it up - or use an old pin for trailering and switch for sailing.
Personally, I am very happy and confident in the current model AI and TI. They have undergone continual improvement since their launch and I trust their sea-worthiness in all but the most extreme sea conditions. I have logged over 4000 miles in Islands including 7/7 EC's, extensive Catalina Channel Island and Baja trips.
