Caravans need permits
The Laxey campsite takes cars, tents, motorcycle and motorhomes but not caravans.
It is not obvious why not caravans.
Of other campsites on the island some take caravans and some do not.
21 June 2016 web searches showed up that since 01 April 2015 it is necessary to have an IOM Government Permit to bring a caravan onto the Isle of Man. This really did not jump out obvious in early 2013/2014 research for LBW on Isle of Man due the three organisers do not own caravans.
Then read at bottom of page.
Steam Packet ferry, vehicle types
Then look down near the bottom, Explanation of Special Restriction Codes, item B.
And then only on the ferry Ben-my-Chree which is mainly Heysham to Douglas in the summer.
Inquire for IOM Government Caravan Permit
or telephone +44 (0) 1624 686 911
At time of writing 21 June 2016 the one known LBW caravan family have taken a holiday cottage in Laxey, and left caravan behind in England, this year because Laxey campsite not take caravans.