Add a mask to this layer and use a black brush with the hardness about 30% to blend the bottom of the boat with the clouds, and increase the hardness of the brush to 100% to clear a part of the top left:

Step 13

To give the boat more light, I used a Layer Style effect. Double click the boat layer, choose Inner Shadow:

Step 14

I used Curves to darken some parts of the boat where are hidden from the light:

On this layer mask use a soft black brush to erase the dark effect on the higher part where is illuminated by the light:

Step 15

I used a Hue/Saturation adjustment layer to reduce the boat saturation:

Step 16

I used Color Balance to match the boat color with the scene:

Step 17

Open the tree image. Use the Lasso Tool (L) to choose the trunk and drag it onto the top left of the boat. Use the Warp Tool (Edit > Transform > Warp) to bend the trunk as shown below:

Use a layer mask to blend this trunk with the boat:

Step 18

Take the leaves part and put it above the trunk and tweak it a little with the Warp Tool to fit the angle of the trunk:

Add a mask to this layer. Use a black brush to remove the unwanted part at the bottom of the leaves:

Step 19

Make the trunk and leaves layers selected and press Cmd/Ctrl+G to create a group for them. Change the mode of this group from Pass Through (default group mode) to Normal 100%. On the top of the layers within this group, use a Hue/Saturation adjustment layer to alter the color of the tree:

Step 20

I used Color Balance to add some yellow to the tree:

Step 21

Make another Hue/Saturation adjustment to reducing the tree saturation:

Step 22

I used Curves to brighten the tree:

On this Curves layer mask use a soft black brush to decrease the light on some parts of the tree to make its contrast suitable for the light in the background:

Step 23

Make a new layer on the top of the group. Use a hard brush with the color #987b47, 4-5 px to paint on the trunk and branches to reduce the contrast of them and make them look more blended with the boat:

Step 24

Extract the child from the background and place her in the center of the boat, flip her horizontally (Edit > Transform > Flip Horizontal) to fit the light direction: