Bases spawning in floor or half way under waterSuggestion
I love this plugin and so does my server but a few things i wish would be added.

Fix for bases so that the bases do not spawn in floor or half way in the water.
Bases to spawn all over map not just the outside of the map what it does 90% of the time.
Able to have 4th tied for high metal , like easy, med, hard and extreme.

have another look at the raidablebases.json file

- there are settings to fix for the water

There's another plugin that works with raidablebases that can control where they spawn - i can't rmeember which.

There are 3 more tiers planned but not yet introduced,  i too have asked when this will be.

Please keep requests and issues to one per thread to avoid duplicates, thanks.
How to prevent the raid bases from going in the terrain or water: Look at the foundation lowest to the ground and type /copy {name of the base}

If you would like to manually the spawns for the raid bases use the spawns data base plugin by k1lly0u. I like using this plugin to avoid the raid base from going underground.
To fix this perminantly,
would it not be possible to find the lowest foundation co-ordinate, then use the actual player mechanics to try and palce that "fondation" item.
if it cannot place, then it's likely the foundation is below the map co-ords....