Yes.
No, they just have different jobs.
Some people think that a Navy Seal Sniper is safer than Navy Seal Infantry. Some people think that Navy Seal Infantry is safer than a Navy Seal Sniper.
Navy SEAL. If you can take it.
On average, one Navy Seal can expect to get at least 10 different deployments in a 20 year career.
{| |- | It occurred off the coast of Somalia. The Captain and the pirates were in a lifeboat being towed by the Navy. A team of Navy Seal Snipers stationed on the fan tail of the ship took out the pirates. |}
SEAL.
Navy Seal training lasts about nine months.
Special Operater. Navy SEAL.
A Navy SEAL can become a sniper, then an officer if he has an education.
You can't serve in two different units simultaneously. Some Navy SEALs do attend Ranger School, or else they've attended it prior to attending BUD/S to become a SEAL.
Any U.S. Serviceman can become a SEAL, as long as the educational, physical, and madical requirements are met. In the case of a Marine first said marine would have to serve his obligated contract with USMC, or get a waiver and sign new contract of enlistment with the navy. Just talk to your career counsellor and get guidance on proper course of action. But the answer to the question is, YES a Marine can become a Navy SEAL, there are just a few more steps to climb. In any case if being a SEAL is the goal then that person will find a way. I know several former Marines that are in the teams now.
There are several places one can purchase a Luminox Navy Seal watch. These retailers include Amazon, NY Watch Store, Watch Co, and Tactical Distributors.