I had the same problem with the bow cap on my '82 H30. Mooring lines, pulling at a more downward angle than dock lines do, cracked the bow cap along lines roughly parallel to the edges (about an 1 1/2" back from the edges) and actually crushed through part of the starboard edge. There were hollow areas under the edges of the bow cap and not really much strength in the cap itself.
My solution was to drill a series of 1/4" diameter holes through the cap about an inch or so apart along the cracks, inject epoxy filler into the hollows, and build up the crushed area with epoxy. Then I routed out the cracks and epoxy filled holes with a Dremel tool, filled them with MarineTex white epoxy putty, sanded and painted it with two coats of matt black Rustoleum. It looks like new and appears to be holding up OK, but the boat is on a dock now, so I haven't really given it the mooring line test yet.
This cap seems to be a common problem area on these boats. I've seen some others replace it with stainless steel...with varied degrees of success. It may be stronger, but it's a complex shape to form, so you need a very good custom fabricator ($$) or it can look kind of crude.
