This in from Wightlink, in their own words. Ed
Please be advised that from Monday 28 February, the barriers on the Portsmouth-Fishbourne-Portsmouth route will be closing for both vehicles and passengers three (3) minutes prior to sailing, to ensure prompt departure of the vessels to improve punctuality and arrival times, in advance of new forthcoming regulations
Wightlink apologise for any inconvenience that this may cause and would like to take this opportunity to remind passengers with vehicles that they are recommended to arrive at least 30 minutes (but no more than one hour) prior to departure, and foot passengers 15 minutes prior to departure
Wightlink would like to thank passengers for their co-operation.