Getting a horse totally comfortable with water is an ongoing thing trained in very small steps, and definitely not something that can be accomplished or "fixed" in a short time. Eventers spend YEARS getting a horse 100% comfortable with the questions they'll encounter on cross country. The statement you made in your post about "doing prelim with him within 20 minutes" and the issues you described with him rearing near the water is a huge red flag that he is not ready and you are pushing him too fast, horses can't talk but that is his way of trying to tell you that he is not ready for what you are asking. Many horses will jump very big over things they are unsure of, and his jump into the water sounds more like a panicked leap than the relaxed jump in the horse should be making. He still sounds fairly green overall to me.
When you first took him down to the lake the first time, you should have just taken him to where he was comfortable and then just let him stand there. Ask for a step or two forward when he was relaxed, and then let him stand. Maybe he would have went all the way into the water the first time, maybe not, but it shouldn't have been a big deal either way. Praise him big time for every step and any curiosity shown towards the water. Instead of forcing him in the first time, you should have introduced it slowly over a few days or a week, and went very slowly, and shown him it was no big deal. Now he's obviously got some anxiety about *entering* the water, not so much the water itself, it sounds like.
Every thing in cross country needs to be done in baby steps. You start with small logs, then gradually progress to larger fences. This is done over a summer or two, not over a single training session. Same with ditches, start very small and then slowly go bigger. Same with water, you start very basic, just walking and standing, then trotting and cantering through, then walk in off a tiny bank, etc. What you want to do is make the progression very gradual and step by step so there is never an issue, the horse never has a tantrum or gets overwhelmed or says no. This is how you build a good cross country horse with no holes in its training. There's no shortcut unfortunately.
Your horse sounds like he's trying very hard and seems like a very willing and forgiving horse. He also sounds like he's got a lot of talent as well, but he is scared. The good news is that I definitely think you can address and fix the water issue, but it's going to be a slow process. My suggestion would be to start back at square one. Getting him totally comfortable with the water again, starting over like he's a green horse that has never set a foot in the water. Then VERY SLOWLY progress to trotting through, cantering through, a very tiny bank in and out, and so on, and not moving on until he is total and 100% comfortable with the each step. That's the only way you're going to be able to fill the holes in his water training and fix his anxiety. An experienced rider might be able to get on and bully him into the water, but that's not going to make him more confident in himself or "fix" anything. You have to go back and fill in his blanks, which is being comfortable and relaxed entering the water. And you as a rider on a green to cross country horse have to be quiet but confident, firm but not harsh, and extremely solid and aware of your body position at all times.
Another thing, is to make sure that whatever water you take him in, has extremely good footing. If you're taking him into creeks and lakes that have muddy, sucking bottoms that his feet get stuck in, or the creek bed is rocky and hurts his feet and he has trouble walking on them, or maybe there's sticks and logs on the bottom that he may stumble on and can't see, or weeds that tangle around his legs, you're not setting him up for success for jumping into water later. He may not want to go in because he can't see the bottom, he doesn't know it's safe, he may think it will be sticky or rocky, maybe the water is a slightly different color, etc. When I am introducing a horse to water, I make sure that the first 5 or 10 times I do it it's in a very simple, laid back, and inviting way, with lots of confident friends around to give him a lead and calm him, and I make sure it's in a proper water complex with a well maintained bottom. And I don't make it into an issue, there is no schedule set in stone, you really have to read the horse and listen to what they're saying. If they're not ready and acting up, listen to them, stop pushing, and end the session on a good note. Then you try to progress a little more next time. You really have to set the horse up for success from day 1.
Last edited by albertaeventer; 05-17-2013 at 04:02 PM.