Hi Ingrid
There are only private tours available from Inverness to Skye in early March. Coach operators start slightly later.
To clarify some of the points another poster made.
It is very easy to get to Inverness by flight (Gatwick and Luton). Heathrow flights are going to start in May.
The website listed http://www.scottishtours.co.uk/tourindex.asp?departure=3 won't have any tours for that time in March starting from Inverness. It is fact just an agent's website and not a tour operator. The tour operator in question is Highland Experience tours - their 2016 tours start March 21st. The other tour operator out of Inverness is WOW Scotland Tours - their summer schedule starts April 9th.
So, in summary - only way to do it from Inverness at that time of year is to a) rent a car b) take a private tour (there are quite a few companies which offer these - check out TripAdvisor).
Hope this helps!