Are they areas used by the MOD near to firing ranges?

The few feet of water in front of that giant supertanker!

shallow bits, wrecks, exclusion zones round big ships (like jamie said), fishing boats and lobster pots.

oh and cherub sailors.

Submarine/mine sweeper magnetic loops

Gunnery ranges

Commercial wharves (terrorists)

whales

For me, when I raced the B14, it was just any slower boat.  Downwind, Mirrors just become stationary objects to drive around.  The rules just seemed to work better if we kept clear of everyone.

Not wishing to flame you in paticular, but there seems to be a growing attitude that all I need to know to pass is in the handbook.  That may be the case but the handbooks do not provide anywhere near enough info to be a good instructor. Which is why asking questions on forums such as this and doing some more in depth research is a commendable attitude to have. If you want to be an instructor aim to be a good one!

The hand book is a basic out line of what you need to know. You own knowledge is what makes you a good instructor and you need to be able to put it accross in a good way.

as in instructor you will always be gaining experiance and passing it on to others

Experiance is what you get when you dont get what you want

Assuming this is a hazards talk which group is it aimed at as the content emphasis is different for L2 to how you might approach seamanship or daysailing.  For L2 (off the top of my head as I haven't checked the syllabus in the logbook) I would want to cover:

Hazards when rigging - overhead power lines, lifting, long masts (what's behind you)

Hazards when launching / recovering - Slippery slips, edge (deep or rough) other users, cars, leeshore, offshore.

Weather - what's forecast, does forecast = what you see, emphasis (at this level L2) correct sail plan, don't go if you're thinking about it, sailing area and what to do if weather closes in.

Navigation hazards at sea - other shipping, deep water channels, rocks, tides, shallows.

Letting someone know (where, when back and what to do if don't return)

Inland waters weirs, pumping stations, fishermen, overhead cables, locks, leprospirosis.

How to get this information.

With adults I would probably introduce the topic and set out some major headings and then get the students to brainstorm the hazards they can think of - then add any they've missed, summarise and tell them where to get further information if they went to a new venue (Harbourmaster, local SC etc).  alternatively if it was a windy day full of lectures (to give them a break) I would walk around the sailing centre discussing the hazards and just do a quick summary in the classroom.

That is probably more material than your ten minutes so you need to keep things moving along briskly.  I would prepare a brief summary to handout at the end as adults love to collect paper (and your theoristrs and reflectors will be able to review).  If you tell them you have a handout it prevents some taking notes so they can concentrate on what you say.

If it was juniors I would draw a map (with pics) on the whiteboard and brainstorm by getting them to identify the hazards they see and rather than notes some sort of worksheet (say a wordsearch with pictures of the hazards round the borders).

The SI workbook has a very good section on lectures and a planing sheet (you can download it from the RYA website).

Hope this helps.