H18 vs H18SX they preform about the same. SX's might have a slight edge on power but they are also a little heavier so I would call them equal. I sail my 18 as an SX for fun sails and I change it to a standard 18 by changing out the mast and sail when I'm racing Hobie one design.
I will be at the 18/20 North American next weekHere's my priority list for buying H18's. Currently I have 3 last year I peaked at 7.
Hulls are my top priority:
1) DO THEY HAVE ANY SOFT SPOTS?
not a deal breaker but I consider a boat a parts boat if there are soft spots forward of the front crossbar Unlikely on this new a boat but still possible. Also some sellers do not know what soft spots are.
2) I look at the 4 crossbar connection points on the underside of the hull to see if and how much cracking there might be if any.
I do this to judge how hard the boat has been used3)I look for damage that has been repaired and how professionally if was done.
Metal Parts Mast, Crossbars and Rudder Castings:
4) I inspect the crossbars for cracks and corrosion. Closely look around the mast step base for any cracks and where the crossbars connect inboard to the hulls
Crossbars are not hard to replace but used they will cost about $150 to $300 5 I Inspect the mast for being straight. Look at the condition of the comptip.
If the sail track in the comptip is chipped or broken its not hard to replace about $80. 6) Look at the rudder castings to see if there are any cracks.
Soft parts SAILS & TRAMPS
7) I look at Sails and Tramp for condition. If this boat has the original Mylar Laminate sails then plan on replacing them. Even if they are not showing delam now they will soon. You can buy replacements form Hobie or aftermarket. Used OEM SX sail are rare and are not easily to find or their junk.
Myself I'm using a Hobie Tiger Main and a custom aftermarket Jib. They seam to pair well together. I inspect the sail for rips, I look at all the batten pockets, and condition of the bolt rope. For the Jib look at the zipper condition.
Zipper can be replaced. SLO SAIL and CANVAS has replaced several for me.9) I consider the age of the sail. Are they crisp or blown out.
10) I look at the condition of the tramps. I look for rips, tears, grommets pulling out and overall age. The main tramp is still available from Hobie in mesh or vinyl there are also a number of aftermarket but OEM is still the best quality. If you decide to purchases aftermarket some are good and some are not! Search this site for more info.
Wings:
11) Inspect for cracks or prior repairs, covers are available.
Rudders and Daggers
12) Overall condition are they chipped or do the need some care.
These are low on my list because there are lots of used ones available and they are not difficult to refresh.Overall Completeness:
13) I look for overall completeness and judge value accordingly.
14) Is there any extra or upgraded equipment. Blocks, Down haul, EPO's ect.
Keep in mind there are some thing you should replace as maintenance if you don't know their age. Side shroud anchor pins, standing rigging.
My current SX is a 1991. It had been stored in the back of a boat yard for 10years and not moved.
Moss grows on the north side of things When I bought it the tramp had rotted out, it only had the port side rudder. I was given a Prindle rudder for the starboard side, the mast hinge was also missing. I paid $900 for it and think I got a great deal even though it need some love.