I have “repaired” through and through cracks that were leaking in composite canoes with Gorilla Tape and the result was so good I had to sort of force myself to do a proper repair.
With the damage where it is right in the center of the V bottom you have geometry working for you as any external force will approximate the crack, if any, rather than cause it to distract.
If you do find disrupted fibers I would apply an external patch of 6 ounce per square yard S fiberglass. S fiberglass is significantly more expensive the the common E fiberglass but also considerably stronger and more abrasion resistant. And you won’t need more than a yard of it. Cut any patch with its fibers on the bias so that the fibers of the weave and the warp cross over the ridge of the V bottom at a 45 degree angle rather than perpendicularly. That will double the number of fibers crossing the linear crack.
Personally I wouldn’t mess with reapplying gel coat but you can if you want. You will never get anything close to a color match with it. I just paint over the repaired area with any paint that is a reasonably close color match. Of course, the paint will get scratched off and scratched up over time. At which point you just get out the can and spray on some more.
I really like sweet composites for repair fabrics. The type of S fiberglass that I have used and recommend is the style 6533 which is $23 for a 36 x 60 inch piece which will be much more than enough.
I also favor West Systems epoxy and would use the 105 resin with the 206 slow hardener. Sweet also sells epoxy but you really won’t need that much and might not want to shell out a total of $60 for a quart of resin with the appropriate volume of hardener (although epoxy is very handy stuff to have around). Sweet also sells “repair packs” that contain 19 grams of 105 resin with the appropriate pre-packaged volume of hardener. The hardener is the somewhat faster 205 version so pot life is shorter, but you won’t be mixing up much epoxy at a time for a patch of limited size so that is not an issue. Six such repair packs should do the trick and will set you back $26.