An interesting article here, about problems facing the Yemen Coast Guard. It also talks about an ambush of four US advisers to the Yemen Coast Guard that left three wounded, one seriously. The advisers, and the agency they are employed by, are not identified.
The US Coast Guard has sold at least two 87 patrol boats to Yemen. This area is going to be a long term problem, and if the Coast Guard is not already helping, we can expect they will in the future. There is a Marine view of the situation in Yemen here.