I have spent ages trying to find something the right size to make into a life buoy, in the end I gave up looking and decided to make one from Milliput.. Rolled then wrapped into a ring.
Of course if you have a life buoy you need a holder, made from plasticard
and some 15mm plastic water pipe.
It looks better painted and fitted to the wheelhouse.
With the life buoy slotted in..
I came across some resin fish on ebay for £2 they just needed painting when they arrived. Then I made a tray for them for from some plasticard offcuts, painted blue.