RFPNW inland sea service/national crossover hack

SO the sea service requirements for RFPNW are 180 days of seagoing service of which only 90 days may be Inland (or 60 days with a CG-approved course of which 30 can be Inland).

However, there is a National rating crossover table that says A/B Special as an entrance path to RFPNW requires no additional sea service, and it requires 180 days in any waters.

So is it right to interpret that someone can use 180 days of only Inland to get around the OC/NC/GL req for RFPNW so long as they also get national AB?