You need to get a copy of the title to the land in question. You can get this at the same place where you filed your title when you (or another) purchased the property. Lawyers are very affordable here. It should not cost much for one to get a copy of the title. After you see the title and the history of the property you can then make decisions as to what to do.
With seawall or without, if your legal property has a mohun / border marker, and the beach is government / public land including the environmental protection zone, and now people are settling there, they are illegal. The question is, who will help you out. Normally the barangay / municipality should take care of this. If they don't you have a problem. You go to court, this decision can take a lifetime. Maybe you can try to buy out these people.
I think to go down that route would only entice another lot to move in once the word gets around that there's free money available.
you are right, but unfortunately the news spread around already. some people know they can make money by occupying land. specially if foreigners are involved. guess also some people in our area use that business scheme. but some people are really poor and just need land to settle down.
I have experience with this,, the proper route is to play their game.. Ask how much they want to move. When they give you a price say ok, i am going to give that amount to a good lawyer and you will get nothing. Any competent lawyer has connections with the DENR, City Engineers Office. DOH,, DOLE, Noreco if they have electric and DCWD if they have a water connection without a land title. Let the locals handle it just help them out a bit.. These people have turned squatting into a well paid profession even though its against the law.. The city government payed millions to buy out all the squatters on foreshore and private land on the boulevard extension to the north..
This kind of thing seems to be fairly common. As it turns out, my in-laws are squatters and have their house built near the shoreline in Basay. Originally they had a sea view and it was amazing. Then the fishermen started building nearby and eventually one built in front of them, closer to the water. The place closer to the water floods with every typhoon, but they won't move because they own a large boat and the shoreline access makes life easy. Having your sea view blocked would be bad enough, but they also own several dogs that intermate and now it is a pack of 20 snarling mutts that bark at all hours of the day and night. The business has completely ruined the shoreline as the fishermen throw and break their glass bottles all up and down the beach, and litter like they've never seen a garbage can before. The short of this, is that these squatters living there isn't anywhere near the worst of the situation and their theft of this land needs to be handled as abruptly and with as much hostility as you can muster, while keeping it all legal. Do not be kind or you'll regret it.
This is just me but if you have the deed and you have kept up on the property taxs's, than I would hire a local surveyor and after the line markers are spray painted red build a 6 foot wall around entire line and bulldoze any sh*t over and out the wall that is not yours. I have done it. But.... that's just me. best of luck!