If you are comfortable with a stocks and shares ISA, you may as well stay with that. The last 3 years have not been great for equities and it is not impossible that the next 3 years could be better. Turning £8,500 into £10,000 in 3 years would require gains of about 5.6% each year which is not an unrealistic expectation.

Of course it's not impossible that equities could go down. A cash ISA could gain about 4% each year which would turn £8500 into about £9500 although you cannot do a direct transfer from a stocks and shares ISA into a cash one but you could close the stocks and shares ISA and open a new cash ISA (maybe one now and one in April) if this appeals to you.

For the past 3 years I have had my money tied up in a Natwest Stocks and Shares ISA. It has made 14% over the 3 years. I am a student, and I survive off student loans and part time work. For the next 3 years I will not need access to the investment. I am not an overly confident investor and I couldn't afford to gamble on something too high risk. I want to be able to come out at the end of this with hopefully at least £10,000. Any suggestions on where to invest it or where I could get more help?