Use the Git Rot method, particularly if the soft spot is small. You need to fix it before you sail. It's not difficult to do, it maybe takes a little convincing yourself to drill holes in your boat but other than that the repair is pretty straight foward. I repaired almost the entire length of my starbord hull over the winter and it is rock hard, although after the fact I found out that the insides of both hulls were soft which equals scrap more or less. But nontheless the deck is hard as a rock.
Your injection holes only need to be big enought to accept the tip of the Git Rot bottle, the breather holes can be really small. I can tell you exactly the size bit I used if you need me to. Before you drill, mask off the area and mark the soft spot with a pencil. When you start drilling dril down the center of the pontoon for your injection holes. Drill the breather holes just inside where the grippy stuff is (1/2 inch-inch). They don't need to be big at all, and I found out through error that smaller holes are much easier to cover up later. When you begin drilling let the drill do the work. You may want to make a stop so that the drill bit only penetrates about 1/16 of an inch or maybe a little more. You'll be able to feel when you go through the first layer of glass, trust me. Make sure you don't go through the second layer. Like I said, let the drill do the work, only the weight of the drill, get it? I found that it really helps the stuff penetrate if you make channels in the foam using a bent nail, but it will work if you don't. Big difference in the speed of the repair though, and now that it's getting hotter you'll want to work rather quickly as this stuff really sets up quick in high temps. Follow the directions on the bottle and away you go. Fill em up, seal em with tape as they ooze out, and make sure that you do your best to do it all in one go. And from what I learned in hinsight, take the masking tape off right after the epoxy sets to make clean up way easier, and I mean way easier. I left mine on and half on the finish work was getting the tape residue off.
Ask questions and good luck on your repair. If it weren't for the folks on this forum I wouldn't have gotten out for a sail this year. I was totally in your shoes a year ago. This is totally a repair that you can do and you need to do it before you sail. The bow is under a lot of compression and can litterally snap off without that area reinforced. Plus, your feel much more confident in your boat which equals funner, and faster sailing.
If you want to see some of the progress on my repair and get an idea of how I drilled my holes check my beach cats albulm:
http://www.thebeachcats.com/modules.php ... _photo.php
It goes backwards chronoligically.
Good luck and tell us how it goes.