Deep Water, so Deep Water is another H2O technology. The main H2O software we've been looking at in this course has a lot of power. But as I'm sure you're aware, there are alternative competing machine learning technologies such as TensorFlow, MXNet, Caffe, and so on. Each of those has its pros and cons. The idea behind Deep Water is to wrap them, So as to allow you to use TensorFlow, MXNet, Caffe, but still stick within the rest of your H2O infrastructure. So you get to use them as a back end. Now there are a few challenges with this. For the H2O developers, it's quite the challenge to be mapping a back end as a moving target because those libraries keep updating. They keep releasing new versions. This is also related to another downside, which is that Deep Water is quite difficult to install if you do it yourself. You need to be able to install each of those components, TensorFlow, MXNet, Caffe, get them working with GPUs all on the same machine, as well as installing Deep Water. The good news is H2O provides some ready-made setups. So there's an Amazon AMI machine image. There's also a Docker image that you can use. So those solutions help you bypass a lot of the setup complexity. There are two main reasons you might want to use Deep Water. The first is so you can make use of GPUs in your deep learning in particular. The second is to use ready-made models. So this comes back to another pro and con. H2O, in my opinion, makes creating deep learning models just about as easy as it possibly can be. The same can be said for the alternative technologies. They tend to expose a lot more of the inner details. You need a lot more knowledge about how the algorithms actually work to be able to use them. But if someone has already made a very useful model, in TensorFlow for instance, say a very deep convolutional network for image recognition that you want to use. Deep Water allows you to bring in that model and use it, but still stick within your familiar infrastructure, whether it's Flow or the H2O client for R and Python. So if you want to learn more about H2O Deep Water, there are some links on the documentation page docs.h2o.ai. That's the best place to start.
