Let me put it to ya this way...it'll be an interesting experience. Just from my limited experience here riding along the Tennessee river, I've found out that big open water really freaks horses out, especially if has waves. They don't seem to know what it is and don't want it to touch them. Tennessee wanted to run backwards when the waves off of a barge came rolling in. I finally convinced him to step in the water but he was snorting and rolling his eyes the whole time. I guess if you take them there fairly often they get used to it, but he still doesn't like it.
Heh.... I wonder about it! Easpecially because at the ocean the waves will come in, and then completely recede, and then come back at them again.
You see it on greeting cards, horses running on the beach!