I have 3 horseback riding photos from The Gold Mine Ranch on my trip report at the following link (just click on the small photos in the report to make them larger) from last Sept. It was just the guide, myself, and my 2 girlfriends.
http://www.aruba-travelguide.com/tri...ike/index.html
You will travel across the cunucu and over to the rough side of the island. There are a few sandy coves (like you see in the photo) but no real beach riding (horses walking in the water.) You'll only get a true beach ride with Rancho Notorious but they do take larger groups. We used to pay extra for private rides with Rancho Notorious but I see that their prices for that have gone up CONSIDERABLY
since the last time I did one.