array of raycasts in grid based game

Hi im making a battleship type of game and i need to make restrictions on where you can place your ships. I place my ships with the help of an raycast on the cursorposition called with the mousebutton. There i only needed to call 1 raycasthit. But now i want to be able to do the same but instead call an array of raycasthits surrounding the cursor.

  RaycastHit[] submarineZone[];

  Vector3 mousePos = Input.mousePosition;

  Ray ray = Camera.main.ScreenPointToRay(mousePos);
         for (int i = 0; i < submarineZone.Length; i++)
         {
             if (Physics.Raycast(ray, out submarineZone[i]))
             {
                 if(submarineZone[i].collider.tag == "playerTile")
                 {
                     canBePlaced = true;
                 }
                 else
                 {
                     canBePlaced = false;
                 }
             }
         }

I figured it would work like this. The thing is im unsure on how i could efficiently position these raycasthits so that they would surround the cursor in a "grid-fashion". This submarine object is only 1x1 big (just a tile) and to make a correct restriction for it i would need 8 raycasthits that would surround it where it would detect if it hit something its not supposed to next to it.

I could just hard-code these positions but is there a way to define each position of the raycasthits that wouldnt eat up too many lines. OR is there a more effective way to deal with this problem that im not aware of

Thanks