Northstar, I think the flash you mean was a boat going past! It came past pretty quickly but I think it was a fishing boat and when it was heading out it had a huge floodlight pointing directly towards the shore where I was.
Miah, I used a Canon 6D with Samyang 14mm f/2.8.
I took over 400 shots over roughly a 3 hour period, each shot was a 25 second exposure at ISO 6400, f/4 (f/2.8 wasn't giving me great IQ) and then there was a 1 second interval between shots. Just used a basic intervalometer I got off eBay a few years ago.