Caribbean Ponderings

Now our long awaited Longships campaign has finally kicked off, I can now stop preparing for the campaign and return to projects that had been set aside in the mammoth six month painting frenzy. Mind you most of these figures have been in the painting queue for about 36 years so I guess their time was due!
Next in the paint queue are figures for a 28mm Napoleonic Sharp Practice set up that should be hitting the table soon - hopefully I'll have more details in the not too distant future. After that it may well be the turn of the Blood and Plunder pirates that I received for my birthday. I have a moderate size collection of these; certainly enough for a few games but I will need some terrain.
In fact I have already started a Blood and Plunder solo campaign  but in 15mm until I get the larger figures painted. The first 2 games were sea battles, so no great terrain requirements there, although afterwards I decided that my 30 year old sea boards no longer cut the mustard. Hence, I have added a nice sea mat from Deep Cut that has yet to see action.
Unfortunately, the next campaign battle will be a bit more challenging as this one will be an amphibious scenario. My usual modus operandi when faced with a terrain project is to see what crap I have lying around the garage - and this was to be no different. After half an hour's rooting around the darkest recesses of said garage I emerged with a stack of old green carpet tiles. I figured I could cut these into the shape of various land forms that could then be placed on top of my sea mat.
A prime consideration for this is that any terrain should be light weight and easily stored - these would seem to be ideal in that respect.
After attacking the aforementioned tiles with a Stanley knife I was left with the following prototype.

Configuration 1 - the headland

I had originally intended the carpet tile to span the full width of the sea mat but unfortunately the tiles are something like 18 inches square and the mat is 4 foot wide. However, by trimming off the corner of the tile I was able to create the suggestion of a headland.
It also occurred to me that, if I added a couple of smaller bits, I could also create a river mouth,as shown below.

Configuration 2 - the river mouth

Now there may be other configurations possible and I still have a spare tile left but these will do for now.
My conundrum now is what to do next? My current options are:

1) Leave them as they are - a bit naff but workable.
2) Paint them
3) Add sand and flock

At the moment I'm favouring option three but my concern is the possibility of warping if I use sand and pva. On the other hand the tiles are quite flexible and could probably just be bent back into shape. Hmmm, one to ponder. I think it will be option 1 as a stop gap until I make my mind up how best to proceed.