I hear that, my former boat had a galvanized trailer with rusted hardware, pretty standard fare on boat trailers.
(I was joking about galvanized and aluminum being welded.) They actually use explosion welding to create material for interfacing aluminum superstructures and steel hulls. There is a sport boat out of San Diego built that way, 'The Independence'.
For speed and ease of operation, I actually prefer a spoolgun connected to a mig power source of sufficient capacity and a bottle of argon. It almost makes aluminum welding tolerable for me.