Do you refer ONLY to the Turn 1 Sealion based on ‘surprise’ long-range-air ? That is forbidden competitively as far as I know, either explicitly (Turn 1 special rule) or the delayed tech in LHTR.
Or do you refer to the Turn 2 try (after building 2-3 transports, as in the Canadian Shield plan of Caspian_Sub) or the option for Turn 3 with 5 more transports built Turn 2 for a total of 9 ?
Germans - keep an eye not to fall in the reverse trap of ‘successful Dieppe’. Good Luftwaffe exposed in France with too few inf, being invaded Turn 1 by British 2inf 1art 1tnk 2ftr 1bmb (1btl support) with relatively little cost.