Even with sticker eyes the Mavic is too small to scare away seagulls.
They might even use the eyes as a strike point. Maybe painting or wrapping the Mavic in a signal color would help. But I guess the best thing to do is to show that the Mavic poses no threat or competition by ascending quickly, straight up. That shows them that they would have to spend a lot of energy to keep up. Seabirds usually don't waste precious energy. But taking off from a fishing boat places your Mavic straight into their hunting territory, right after take off. Descending back to the boat they will attack your Mavic again. They claim every place with food as their territory. They can even 'attack' kids or a dog on the beach. Inland they chase any small bird of prey like falcons away with the lot of them. Falcons do rise extremely fast to get out of their way and to get the advantage of great height and use that to be able to get an extreme diving speed which any bird knows is killing, even for a bigger bird like a seagull.
My Inspire1 is big enough to impress them (my Phantoms never were and the Mavic is even smaller, and resembles a small bird of prey) and with the nose painted bright signal orange I have little to no problems with them, so far that is.