The Single engine sea plane rating is a RATING, not an endorsement like high-performance or tail-draggers.
True, but also irrelevant.
To be able to instruct in a plane for the purpose of logging time towards an FAA raiting, you need to hold the proper ratings on the FLIGHT INSTRUCTOR certificate, not the commercial certificate.
Yes, and no. There is no seaplane rating on the flight instructor certificate. Only on the commercial pilot certificate. One who holds an airplane commercial pilot certificate with a seaplane rating may not provide flight instruction for any operating privilege or toward any certificate or rating. One who holds a flight instructor certificate with airplane privileges may not provide seaplane instruction unless he or she also holds seaplane privileges on his or her commercial pilot certificate. The flight instructor certificate states nothing about seaplanes, but is only valid when accomplanied by the commercial pilot certicate, and it is the commercial certificate that spells out the extent of the privilege granted by the flight instructor certificate.
So yes, even a private pilot can instruct anyone. But no, it would obviously not be considered useful instruction as it wouldn't count towards anything and is not loggable as dual received by any potential student.
Incorrect. In order to act as a flight instructor in an aircraft, one must be appropriately rated in tthe aircraft, as given in 14 CFR 61.195(b)(1):
§ 61.195 Flight instructor limitations and qualifications.
(b) Aircraft ratings. A flight instructor may not conduct flight training in any aircraft for which the flight instructor does not hold:
(1) A pilot certificate and flight instructor certificate with the applicable category and class rating; and
(2) If appropriate, a type rating.
Certainly the flight time is loggable. If a student intends to obtan a seaplane rating, which is a class rating to be added to an airplane category, then the student is going to require training in a seaplane, and to receive this, he's going to need to be trained by an instructor who is qualified in a seaplane. If the instructor is qualified and the instructor acts as an authorized instructor, providing flight instruction, of course the student can log it.
To say that a private pilot can instruct is not correct. A private pilot does not hold the privilege of providing instruction. While one may attempt to pass on training or knowledge without the instructor certifcate, one may also run into considerable difficulties, particular liability and legal difficulties, should one step outside the prescribed bounds of privilege. One who does not hold a flight instructor certificate may instruct under other circumstances, such as a training center or company training department, but only within narrowly defined guidelines.
Not 100% positive on this but do you actually need to have a commercial seaplane rating?
Yes. See above.
So if you already had the CFI wouldn't just getting SES private give you instruction privileges in SES?
No, see above.
