Greg
Your website is different to large commercial organisations and this works in your favour. If people are going to rent, they are going to do research...so as long as the site has plenty of information and its accurate that is key.
Glossy "piano black" graphics, fancy javascript dynamics, customer reviews, social media links may help but what you have (good detailed, honest information) is best.
If you can make it easy for people to make a decision without crowding out that is best.
If you can get ALL the information on ONE long scrolling page that would be superb - you can have pages linked off - i.e. if someone wants to print off a boat spec or route map.
If it works on BOTH mobile and desktop (i.e. your designer uses a fluid grid) then you don't have to worry who's using it.
When we were renting for our first time this year, we did this:
[a] Searched on location in Google (e.g. "shropshire canal hire", "llangollen canal")
Looked at non-sponsored links first, ignored the large commercial brokers and sponsored links
[c] Looked in priority (i) berths + layout (doubles/singles), (ii) toilet/shower/bath (iii) general spaciousness
[d] Checked availability (i.e. on around +/- 3/4 days) when we wanted to start
[e] Double check all details of boats available
[f] Selected
[g] Booked
Voila.
So I would say if you can get the key points one one long web page:
[1] Routes/options from our base - map plus one week and two week route options
[2] Boats - with at least one decent picture of boat, plus room layout, berths, features
[3] Quick availability lookup matrix (i.e. dates on left, boats across top) and price
[4] Booking bullet points
[5] Minimal booking form to initiate process
Hope that helps.