How do you determine how big of gear you actually need?
Consider static loads, dynamic loads, loading cycles, salt
exposure, UV exposure plus types of use be it cruising or racing
and it adds a lot to the mix. All vendors make different lines of products to attempt to match the major sectors and boat sizes. The last factor is also budget
This isn't a computation you can run easily on a calculator.
Here is a good formula for measuring the area of the sail. It won't compute extra roach area but it will do any non right triangle like a jib
. Where A, B, and C are the basic dimensions:
Square Root of ( .25 * ((A+B+C) * (-A+B+C) * (A-B+C) * (A+B-C)) )
Some tables will help you compute line sizes based on sail areas, but on smaller boats you just go with over sized lines since a smaller line is hard to hold.
With blocks I found Harken
sizes the sheaves to match the line size so it's easy. Schaefer does not they make sheave sizes on some blocks that can't handle a large big block load but they do make multiple types of blocks with 1/2 sheaves. That means it is possible to buy a Schaefer block too light for the load. This means that with over sized lines you may not require the a block as big as a Harken
block would force you into. It's about matching things to the load not so much to the size. Most products will give you a SWL (safe working load) This number is most helpful when comparing The Harken block to the Lewmar
block back to the Schaefer block.
With blocks this gets even more complicated as the really large boat blocks are very expensive with all vendors. If you use the vendor guidelines at least you can get into the correct product line and then pick the block for the purpose.
You just have to watch out the price
point does not distort your judgment when you really need that $80 block but the $33 block would fit the line. When you need 6 of them you can start to think otherwise. I went through almost this situation with the blocks at the base of the mast
. UV had trashed 3 blocks and a face of a sheave sheared off and wedged the reefing line between the cheek and the sheave (as I tightened up the last bit on the jiffy reef point 1). They all were the same age so they all had to find a dumpster.