Dredge/AB seaman

Can anybody tell me if you can upgrade to an AB unlimited from an AB Special working on a cutter dredge? On the certificate of inspection it calls for at least 2 ABs aboard the vessel. The length of the dredge is 206 feet. This is not a hopper dredge it is moved by tug boats. Can anybody help me out??

Probably not, unless the vessel is operating near coastal or on the Great Lakes. AB Unlimited requires 3 years on Great Lakes or Oceans (including near coastal). You can “re-use” any time you used for AB Special, as long as it was on Great Lakes or oceans. See 46 CFR 12.403(a)(1).