Light rescue boats only have one category "Light Boats (General)" in the ARR selection list.
Both my light boat trailers and heavy rescue with light boat units will get selected by this item in ARRs.
2 heavy rescue with light boats will not select on any ARR using the the Light Boats (General)" option. I did reset this to 0 qty on an ARR and back to 1 to test and it doesn't change anything. Happens on Mobile and in chrome.
Also, the newer "Patrol Boat" is not in the Water tab in the unit selection lists.