We have our Tandem Island hardened for offshore use, the stock TI only has a CE "D" rating. Because we go offshore with it we had to harden certain areas of the boat to make it suitable for offshore use. One of the areas that needed to be hardened is the AMA's and the bungy attachment that holds them on.
What I did on mine using 1/4" dia nylon (stretchy) rope, I tied the rope around the front AKA hull braces (one on each side of the hull holding the front AKA bar in place. I then ran the rope to the metal cleat in the center of the AMA. I put a clip on the end that goes onto the AMA cleat so basically the rope is attached to the boat always, when stored I just shove the ropes into the mesh pockets, then when setting up the boat I clip the rope onto the metal cleat on the AMA. I have mine a little taught. This does three things:
1. If the nylon sheer bolt on the rear AKA bar ever breaks, the rope prevents the AMA from folding in (which would surely capsize the boat if under sail).
2. The rope prevents the AKA bar knuckles from popping out while underway (this has happened to us several times), which always has the same result,,,,, we capsize.
3. The rope because it's stretchy nylon puts spring tension on the AMA's so they don't rattle around at all or drop down and sag when the AMA is up in the air. We scuba dive off of our TI and often climb into the boat over the AMA and onto the tramps, without the brace ropes you can't do that.
Now if you want to be extra safe you can add a second line from the rear AKA hull braces (one on each side) up to the center metal cleat in the middle of the AMA, what this does is create a truss type structure, adding even more additional strength. Same situation, you only run the ropes one time, then just unclip them after every use and stuff them in the mesh pockets for storage.
I also recommend that you either shorten your existing bungys (replace them if they are fatigued). You can shorten them by unscrewing the plug that holds the bungy into the hull with needle nose pliers. Cut an inch or so off the end, then re-tie the knot on the end of the bungy and screw the plug back into the AMA. Actually you only need to stretch them over the little cleat to get them on, so it's probably a good idea to have them just long enough so if you push down on the AMA with your had, the AMA can only go down an inch or two before maxxing out the bungy. By doing this you should never have the problem you are currently having (the AMA twisting out of the hole).
If you want to go extra fancy so you can actually have swimmers sit on the AMA's, it will take about an hour and cost about $3 bucks in materials, you will also need some needle nose pliers. Basically what you do is unscrew both of the black bungy fittings and and remove both fittings. Now you go to your Hobie dealer and buy some Spectra string (that grey rudder line they use in all Hobie rudder systems), this stuff is no stretch and incredibly strong ( 700 lb test), I don't recommend anything else (definitely nothing from walmart or Home depot, etc). First of cut off an inch or so of your existing bungy like I described above (it doesn't need to be as long as you have it), then re-tie a new knot on the end.
Now take some of the Spectra string and tie a cinch knot at one end, loop the end thru the cinch knot (like a noose (google it)) then around the bungy (below the fitting) now fish the end thru the fitting along side the bungy cord. To test it you put the plug back in the tug on the spectra string sticking out as hard as you possibly can (try jirking it a few times), it should not move no matter how hard you pull, If it pulls out you have to make a bigger cinch knot.
Now you go over to the other fitting and do the same. When your done you will have a loop of grey string along side the bungy. What I did was make the loop long enough so you can wrap the spectra around the post on the AKA at least once, then pull the bungy over the top of it. It will still be loose, where if you take the bungy off, the AMA will fall about a half an inch to an inch or so before they pull taught. With the spectra string on there your AMA can easily support 300 lbs plus (or until the plastic fitting fail (whichever comes first). The spectra string is around $.30 cents a foot at you local dealer, or mail order ( http://www.austinkayak.com/products/632 ... -Line.html
). You will easily be able to have swimmers sitting on the AMA's, and climbing on board over them (that's what we do).
Keep in mind once you have strengthened all this sacrificial break away crap, if you do happen to hit a dock or something, you are liable to bend and AKA bar, or even break the boat itself vs just breaking that tiny little nylon bolt on the AKA, but I have a feeling it would take quite an impact to damage the boat, and if the impact is that big, chances are something else will be breaking anyway. Besides if your coming in thru surf or something crazy you can always just unclip all the bracing first, then the boat is the old standard.
Should only take an hour of your time and will cost you about $3 bucks in string (keep the extra in your dry bag for repairs)
Hope this helps