Ahoy ERAD,
Here is a list of u-boat kits and their manufacturers that I am familiar with and
that are currently available on the market. There are also some others but I
am not familiar with them.
Revell U-99 Type VII B scale 1:125 length of model 53.1 cm or approx. 21 inches.
Revell U-47 Type VII B scale (same as above)
Revell Type VII C scale 1:72 length of model 93.3cm or approx. 36 in.
Mirage Type VII u-boats scale 1:400 length of models approx. 5.5 in.
ICM Type XXIIII u-boat scale 1:144 length of model approx. 10 in.
Revell Type XXI u-boat scale 1:144 length of model approx. 21in.
Nichimo OOP Type IX u-boat scale 1:200 length of model approx. 12 in.
Mini Hobby models makes copies of the Nichimo and are currently available.
Academy Type IX u-boat scale 1:150 model length approx. 21 in.
The above kit is a motorized diving u-boat but not RC. The hull is quite
accurate in shape but will require rebuilding the area of the propulsion
system ie. rudders, drive shafts, propellers and dive planes
to render it accurate.
The above kits are all plastic styrene kits.
I hope this info is of help to you,
Have a nice day and happy modeling !