I pulled this off of another forum:
See page 8 of the ATP-Airplane PTS and 14 CFR 61.157(a). If you already have both ASES and ASEL on your CPL, you can take the ATP in either a sea or land SE airplane, and it's good for both. Ditto for ME.
From:
Single Engine ATP? - Pilots of America Message Board
Maybe I'm reading it wrong (or maybe he is wrong), but is this actually correct?
I hold an ATP AMEL, and CPL ASEL, ASES, AMES. They were all Commercials before I took my ATP ride, so should I have actually walked out of the ride with "ATP Multiengine Land and Sea, Commercial Single Engine Land and Sea?"
I'm a little skeptical. I did look up that bit in the FARs, and it doesn't differentiate between Land and Sea... but it does mention:
§ 61.157 Flight proficiency.
(a) General. (1) The practical test for an airline transport pilot certificate is given for—
(i) An airplane category and single engine class rating.
(ii) An airplane category and multiengine class rating.
And
2) For an airplane category—multiengine class rating:
(i) Preflight preparation;
(ii) Preflight procedures;
(iii) Takeoff and departure phase;
And so on...
I know that AMEL and AMES are two different classes, and that's why I'm skeptical. However, why would the regs in this part of this section differentiate between single and multiengine, and not land and sea? I understand why they differentiate later down, due to the different requirements of single vs. multi, but it seem like here, "The practical test for an airline transport pilot certificate is given for an airplane category and class rating" would be sufficient.
I don't know either way, maybe someone can shed some light on whether this guy was onto something or if he's just blowing hot air.