You need to heat the thing thru. Lower heat = more time.
The water bath thing was for back in the old days when ham actually had fat in it (remember lard, etc?). The fat would drip into the water and not be so likely to catch on fire, which used to happen when raw ham was baked for a long time.
Of course, now that ham is lower in fat, the water-and-foil thing actually does add a bit of moistness, so it's not a bad thing.
Glazes, etc, help out the flavor - you can stuff cloves into it in a nice pattern, or use a glaze of some kind of fruit-and-sugar. (Duh, jelly) Apricot jelly is good, Pineapple juice heated with brown sugar is classic, and then you serve the pineapple with the ham.
You can: spread the glaze on at the beginning, and keep reapplying it every 15 or 20 minutes - watch out, the glaze browns quicker than the ham, and you don't want it to burn.
OR, wait until the last half hour to glaze.
However, you can also just throw the thing into the oven, heat, and it. It's really good that way too and a lot less trouble. If you want flavor enhancement, spread with the sauce of your choice at the table.
I'm getting hungry 😀 .