I just had this show up in my inbox from Navionics. I use the Platinum+ maps and I love them. I think you can buy them online at www.navionics.com and I know that Bass Pro and West Marine have them. I use the 907p+ and it has all of the offshore wrecks already programmed in on the maps.
So in case your interested here is the info on their sale according to their e-blast.
Save $30 on Platinum+ marine charts and HotMaps Platinum lake maps throughout the month of April.
All Platinum products include the same chart content and advanced features as Navionics+ and offer additional viewing options: 3D View, satellite overlay, and panoramic photos, that enhance any boating experience.
Platinum+ coverage areas are available worldwide, while HotMaps Platinum covers more than 22,000 lakes throughout US & Canada. Check our compatibility guide, which is continuously updated, for a complete list of compatible models from B&G, Humminbird, Lowrance, Raymarine, and Simrad.