From the first picture it looks like some or your base is missing? But in the second it doesn't look that way at all. Fuck I am confused.
Regardless, (as I would tackle both the same) go get yourself some epoxy, I recommend west system's G-flex epoxy (the plastic one) just because it is what I have been using and it holds up great. If not, most plastic/ marine 2 part epoxies that you can find at any hardware store will be fine, JB weld seems to be a staple for most here.
First thing is first, try to clean out the delam, I use a wet paper towel and follow up with a dry one to get all the water out. Don't worry about your core getting soaked as most cores don't extend fully to the tip.
Mix up your epoxy and apply it to both sides as best you can, if you have a putty knife or anything similar I would use that to push it deeper into the delam, try your best to to make your ski delam more at this point.
Get a couple of c-clamps and clamp your tip down as tight as you possibly can, a lot of your epoxy will squirt out, I'd wipe it up asap so you don't have to sand it off later. Put something between the clamps and the ski like a straight piece of metal or a thin piece of wood on each side to distribute the pressure of the clamps over the entire delam. Let it set and you're good to go.
