A bit hard to tell from the photos, but I'd agree with the others thinking that it is probably just cracked/crazed gelcoat and isn't a structural issue. The West manual has lots of detailed info on the subject and it isn't hard, but the key to success is the preparation. You can't just slap in some epoxy into the crack and expect it to last, you have to open up the 'wound' and give the epoxy some surface area to adhere to. By the time you get finished preparing the area, it will look a lot worse than it does now, but once you build it back up with epoxy and fair it out, you'll have a good repair that will last. Then you can think about painting to blend it in.
As far as epoxy goes, West is great stuff, but it is expensive and most of their products are 5:1 ratio which is easy to screw up (seems simple until you are in the middle of a repair and realize you have to quickly mix up another batch before the first kicks). I prefer the 2:1 ratio epoxies like System Three, Progressive, Raka, etc... They are easier to mix and can be found at close to half the cost of West System.
I'm currently finishing a deck recore on my Alberg 35 (Magic #16
) and have gone through 8 gallons of System Three and almost 11 gallons of Progressive (I switched because supplier was much more convenient). I feel like I've got a good understanding of the different epoxies out there and for the type of repairs most boaters are doing, the additional cost of West isn't warranted. I'd probably use it if I were building a freestanding carbon fiber spar or airplane wing (or something that is engineered to cutting edge tolerances and demands the best), but not for rebuilding decks or gelcoat repairs.