Getting our poodles to have stronger water entries is difficult, most of it is due to their heritage. Watching them, even ones that really enjoy the water, is fascinating. They will often watch where the bird lands then, go along the shoreline until they wind it then they go in after it readily.
What we have to develop is a lot of trust so that they believe us when we send them they know there is a bird out there. It also has to be fun.
One way I have gotten several poodles to swim is to deny them any retrieving except water retrieves. Let them watch as you train other dogs to retrieve or just play fetch with other dogs, get them so worked up they want to retrieve anything! Do this for a couple of days, then after the teasing, try them in the water, hold them back while the other dogs do a couple of retrieves then let the reluctant one go for a water retrieve. Throw it far enough to test their desire but not too far, its a fine line to learn, you can always throw another bumper/toy if it is too far so they have success. Then hold them back and play with the other dog(s) again , repeat next day. If you can find large areas of running water you can build up their confidence of going long distances in water. If they are very birdy they must always get birds in the water not on land, you can make a bumper as good as birds with a lot of wings attached to it. And always lots of play reward for any water retrieves but keep pushing for more difficult ones.
I spent all last summer just getting a dog to like the water. The other stuff, like better water entries, delivering to hand, etc. can be worked on separately and later.