Some general rules: plan your route, watch the weather, pick the right tides, pick the right time of day (leave enough time to get home again, or to allow for snags), take all the necessary safety, navigation and communication equipment (including personal protection from the elements), let someone know what you are up to, and take at least 2 engines (in other words, in the size and type craft you are using, take a least 2 boats).
Many moons ago, when I was in the military, we would take SIBs (granted, a bit larger than yours) from Poole Harbour to the Isle of Wight (and beyond: I seem to remember some teams actually circling the Isle of Wight before heading back to Poole again, but that is a long day out).
As I mentioned, one of the golden rules was always to have at least two engines, in case one packed up (either twin engines on one boat, or two boats with single engines).
Although the best rule to follow is common sense (enhanced by having someone along with plenty of experience).
I think you would be surprised what you can achieve when all the right things are in place - you just need to eliminate as much risk as possible.