I'm putting together an '82 H16 with piece parts from three different boats. I have three sets of rudders. One set is a hard plastic or fiberglass material which is fairly light. Set two is also a hard surface material but seems to be a lot heavier in weight than the first set. The third set is also heavy and dense but has more of a rubbery or hard vinyl feel to it on the surface. Can anyone tell me what I have and which one I should put on the boat?

Set one sounds like either fiberglass racing rudders (gelcoated) or EPOs (epoxy). Either of these are of foam sandwich construction and far superior to the others. Set two sounds like standard plastic (sometimes referred to as lexan). Set three could be ABS...Hobie made ABS rudders for a while.

Well, the first set is attached to the later model adjustable tiller arms with the sliding set screw so I guess that's the ones I'll use. What is ABS?

ABS - Acrylonitrile Butadiene Styrene

It's a common thermoplastic used to make light, rigid, molded products such as piping, musical instruments (most notably recorders and plastic clarinets), golf club heads (used for its good shock absorbance), automotive body parts, wheel covers, enclosures, protective head gear, vballs [reusable paintballs], and toys including LEGO bricks.

It was the original Hobie rudder, unfortunately, they tend to get brittle over time and break off right below the rudder casting.

So I am guessing that mine are probably the ABS?

Hard to tell from the photo, but that looks like PCG or Lexan... not abs. The PCG / Lexan blades had a slightly rough (not glossy) finish and swirl look.

I agree with Matt - a dead giveaway is the "wallowed out" upper casting hole. You can see the plastic deformation (little ridge at the edge of the hole). ABS is too brittle to do that.

The rudder's also got that waxy, semi-translucent look to it that's typical of Lexan. ABS rudders look like PVC pipe - solid white (or yellowed white as the case may be).

BTW, the only place where Lexan rudders break is that corner by the upper casting hole. Once that breaks, the rudder's done.

Well we were trapped out yesterday in a 12-15 knot wind and my starboard rudder snapped off. This was set number one that was hard and light. There doesn't appear to be any structural component (fiber or laminations) in it so I'm assuming it was just some cheapo plastic like ABS. I'm going to replace it with one from set two, the hard, heavy rudder set. Does anyone have an opinion on whether I should replace rudders in pairs? Other than, if my starboard rudder sheared then the port rudder can't be far behind. Also, after I cleaned the dirt off set number two I found an "M" embossed between the two holes and, above that, the letters "XX 1" and "AH" engraved on them. Anyone have a clue what that means?