Training - Ask IYT
With your total experience there are a number of options you may want to consider:
In each case you will need at least to obtain your STCW '95 Basic Safety training, this is a 5 day course (do not do a 3 day version available in some Caribbean and US Locations as they are not recognized by anyone except the US in US waters). The 5 days include fire fighting, first aid, personal safety and Sea survival.
It is almost impossible to get a job without this now.
1. Plan to arrive in Ft Lauderdale in late September/ early October. There are a number of Crew Placement Agencies with whom you can sign up at no cost to you. Crew houses are available where you can stay while you look for a job. Rates vary but you are looking at about $150.00 or so a week for a shared room
Crew houses are great for networking, and there are a number of marinas and yards that you can "walk through" and pass out resumes etc. The Ft Lauderdale Boat Show is on at the end of October and there are frequently opportunities for day work wich then may lead to a full time job.
2. With your experience you may like to think about obtaining a certificate of competency, the beginning level is the Master of Yachts 200gt Offshore (or MCA accepted Equivalent). You would need to demonstrat 3000 n miles in an executive capacity, 50 days at sea etc. and you could then take the course. Armed with this and after obtaining experience in the industry you would be in a position to move up the career ladder.
3. PB 2 or its equivalent is a useful certificate as it is often being requested by Captains for their crew who are responsible for using the tender. The Thames BM License helps to show your prior experience but may not add to your employability in this industry. Operation of a Yacht from a seagoing perspective is a very small portion of the crew responsibility. Service, discretion, presentation, hospitality, safety, entertainment etc are what the average owner and charter guest are most concerned with.
I hope this helps with your future, please do not hesitate to post on here or email me at firstname.lastname@example.org
Just an additional point.
You should obtain a B1/B2 visa for multipe entires into the USA.You will be using this as a tourist to enter. The entry visa immigration will give you will not allow you to work. However once you get a job the visa may be changed to allow you to work on the (non US regitered vessel) whilst in US jurisdiction.