Bottle trap on a bath

waterboard rules and regulations have changed many times during my lifetime and I remember Years ago it was recommend to fit a 3 inch deep trap to everything and the shallow long bath trap was only invented in the late eighties or early '90's, so there are thousands out there done that way,

You'll find many shocks and surpizes , some funny, some not, I once found a snake in a boiler cover, I'd gone to service the boiler, the house owner kept snakes as a hobby, one had slithered in the boiler cover for a warm, I took the cover off and dropped the cover on the floor and shouted ,
" what the fuck", the owner came in and moved the 8Ft coiled up snake, I asked him was there any more about, he promised me there weren't but, It was a quick service and pronto exit,