Of the three, given how much you really want Skellig Michael, I would drop the Cliffs.

That said, I have seen the Cliffs from above, albeit before the Visitor Centre was built, and from the sea and I much prefer the boat tour. If the Cliffs win.

Lots to do in Killarney National Park. I know about the hard choices. If I lived in Ireland I probably wouldn't get to see and do all I want.

In terms of a 9 day holiday, Kerry would give you most bang for your buck i.e. your time :) with some much to do within a short distance

i'd go with the Skelligs but be a little flexible because even in nice weather the seas may prevent the trip. I brought my American cousins there this year and it blew them away. There are loads of operators here but book early because days can become full fast as boats can only take 12 people.

don't worry because there is loads to do around the area is you had to wait an extra day for the skelligs http://www.activeme.ie/guides/drivin...guide-ireland/

I'd most definitely recommend to take a 10 min boat trip or 0.5hr kayak to the uninhabited Beginish Island just beside Valentia Island to visit old Viking settlements, glorious beaches and have the island to yourself for great Walks.

Around Waterville on the Ring Of Kerry are NUMEROUS antiquities worth exploring, should Skellig be delayed --
Ring Forts:
http://www.theringofkerry.com/caherg...nabuaile-forts
http://www.theringofkerry.com/staigue-fort
Either of these also have links to Abbeys and Castle and more.

If you DO decide to forego Skellig, you might consider adding a trip to Inis Mor, from Galway -- by PLANE:
http://www.aerarannislands.ie/
Competitively priced with the ferry and quicker, too! You could even incorporate a 'fly by' of the Cliffs -- making it a 'two-fer'. That would save you a couple (or four or five!) hours of travel heading TO Galway from Kerry.

Those are great ideas, everyone! I've come back around to the Skelligs and am going to investigate motion sickness medications (oral and patch). But it's fantastic to know more about sites to visit in the area if the trip is cancelled, too.

So at this point we have two nights Dublin, two nights Kilkenny, two nights Killarney (I just booked the family room at the Friars Glen, and the nice hostess said she would have breakfast ready for us early on the Skelligs day--I'd rather drive in the morning than have to pack up and move yet again; we're doing a lot of that this trip!).

The last three nights are still up in the air, although we do have to end up near Dublin airport to catch our flight home--the current plan is to see Newgrange on the last day. Any suggestions?? I'd love to get this part of the trip sorted!