What are boards with removable fins called? And under £100?

[jwardmagic]

What kind of surfboards are ones with removable fins called? I plan to get a noho balance trainer to help me practice my pop ups (I really want to perfect them but can't get to the sea too often) and it requires a board with removable fins. Preferably, it would be a minimal board, 7'6'' or larger (as I'm a 6foot 22 year old adult and learning).
I'm hoping I'd be able to find one for less than £100.

[drowningbitbybit]

What kind of surfboards are ones with removable fins called?

Erm, a "surfboard"

That balance trainer seems an exceptionally good way to wreck a surfboard.

[jaffa1949]

Cut out a piece of very thick plywood the size and shape of your board. pop up on that

[billie_morini]

Remove the fins from the surfboard?!
I never heard of that.
All I can do is remove my surf board from its fins.